Very cold temperatures can cause hypothermia, or dangerous overcooling of the body, which can be fatal in the absence of medical attention. Frostbite, or freezing of the extremities, is also possible, along with trench foot and chilblains.[i] Cold-related illnesses can be caused by cold temperatures, strong/cold winds, dampness and cold water.[ii] According to the Health and Safety Executive’s Construction Industry Advisory Committee, workers are particularly at risk from cold when the ambient temperature is below 10 °C. At an air temperature of 10 °C, if the wind speed is 20 miles per hour, the effective temperature is 0 °C.[iii] Average temperatures in the UK can be below 10 °C from November to April.[iv] [v]
In this feature we look at the potential side effects of working in cold environments, what the health consequences are at different temperatures and the legal obligations placed on employers to prevent them.
WHO IS AT RISK?
Anyone working in a cold environment may be at risk of cold stress. Some workers may be required to work outdoors in cold environments and for extended periods, for example construction workers, those in fishing and agriculture, caretakers, police officers, emergency response and recovery personnel. Indoor workers may also be exposed to cold environments, for example, working with frozen food or other cold processes or products.
Cold temperatures can cause blood thickening, increase in blood pressure and tightening of the airways. As such, people who already have chronic health conditions may also be more vulnerable, for example, those with Chronic Obstructive Pulmonary Disease (COPD) have a significantly increased risk of ill-health and hospitalization during periods of cold weather.[vi]
LONG-TERM EXPOSURE TO COLD
A few studies have investigated the effects of long-term exposure to cold working conditions. Work in the cold has been linked with respiratory disorders, musculoskeletal disorders, cardiovascular diseases and skin disorders[vii] (general exposure to the cold is also associated with all of these[viii]). For example, a study of seafood industry workers in Norway found that workers, who often felt cold, had significantly increased prevalence of symptoms from muscles, skin and airways while working.[ix] In addition, exposure to cold can increase the manifestation of symptoms of some underlying chronic diseases.
Let us now look at each of these in turn.
Jammes and colleagues found that daily exposure to temperatures between 3 and 10 °C, for 6 hours, elicited a modest, but significant, airflow limitation, accompanied by bronchial hyper responsiveness, with the effects beginning within 6 months of exposure[x]. It has also been reported that chronic hyperventilation of cold dry air in cross-country skiers, for several years, may induce permanent bronchial disorders and induce ventilatory limitations during intense exercise.[xi] Studies have found that the risk for chronic bronchitis and bronchitis symptoms is elevated among outdoor workers,[xii] but studies tend to focus on populations living in cold areas, such as Finland. A review of health problems in cold work by Mäkinen and Hassi recommends that work activity is planned, so as to avoid, or minimise, very high physical activity levels.[xiii]
A HSE report on respiratory disorders reveals that participants in the 2009/10, 2010/11, and 2011/12 Labour Force Surveys, who reported having breathing or lung problems made worse by work, were asked to identify, in general terms, what it was about their work that was contributing to their ill health. 20% reported that it was the ‘general work environment (uncomfortable – hot/cold/damp/wet/dry/etc)’.[xiv]
Studies of indoor work at cold temperatures, particularly in the food processing industry, have found that musculoskeletal symptoms are more frequent in cold store work and similar conditions compared to normal temperature work, and symptoms seem to increase with longer time spent working in cold conditions.[xv] Local cooling may increase the risk of musculoskeletal disorders in the neck-shoulder region, shoulders, wrists and lower back,[xvi] and a study of seafood processing workers in Norway found that work in a moderate cold environment (including, for example, a moderate ambient temperature but contact with cold seafood products) is a strong risk factor for all types of musculoskeletal problems.[xvii] One review reported that the risk of carpal tunnel syndrome (CTS) was 2.2-fold with repetitive wrist movements, when compared with non-repetitive movements, and 9.4-fold for repetitive movements with cold exposure. Another article reported that work in cold environments gave an odds ratio of 3.52 for CTS,[xviii] while a study of frozen food workers found that cold and repetitive movements were risk factors for CTS.[xix] It has also been reported that repetitive work in cold surroundings causes greater muscle fatigue, which could put a worker at greater risk of ‘overuse’ injuries[xx]. A study of workers in a meat processing factory found that the unadjusted incidence of tenosynovitis/peritendinitis among female sausage packers was statistically higher than that of female sausage makers of the same age[xxi]. The most notable difference between the work conditions of these groups was the ambient temperature. The packers worked in a temperature of 8-10 ºC, whereas the sausage makers worked at 20 ºC. Similarly, a study of workers in a meat processing factory in Colombia found that there was a high prevalence of musculoskeletal disorders among the workers who faced greater exposure to cold, especially in the low back, neck and shoulders.[xxii] A 1997 study of patients, selected from a GP register in Greater Manchester, reported that men who worked frequently in very cold or damp conditions had a 4-fold and 6-fold risk respectively of shoulder pain and disability.[xxiii] A 2010 review found that neck-shoulder symptoms were negatively related to frequent outdoor work.[xxiv] However, in their review, Mäkinen and Hassi point out that, although the literature tends to suggest that there is an association between cold exposure and musculoskeletal disorders, many of the epidemiological studies have methodological limitations.[xxv] A large, more recent, Swedish study, found that construction workers in colder environments were at greater risk of developing low back and neck pain than those in warmer environments.[xxvi]
Further, exposure to cold, such as being outdoors early on a winter morning, is the main trigger for symptoms of vibration white finger.[xxvii]
Mäkinen and Hassi did not find any epidemiological studies that examined cardiovascular problems with an emphasis on work in cold environments, though they did find some studies which were suggestive of the fact that function of those with hand-arm vibration syndrome lessens in cold weather. However, exposure to cold is strenuous for the heart, and its increased workload may be exacerbated by physical activity or work in the cold. Studies have found that blood pressure is higher in winter among those with hypertension,[xxviii] and that this effect is greater in older patients,[xxix] A Korean study compared workers who spent time in a cold area, more than once per day, with workers who were not exposed to cold, finding that the group exposed to cold had higher blood pressure.[xxx]
Analysis of data from two large studies found that more cardiovascular disease events were reported in the winter in both investigations.[xxxi] There was a significant increase in risk of first incidence of cardiovascular disease during cold spells of the British Regional Heart Study (BRHS), particularly among those who had ever smoked. No increased risk was found in the PROSPER study.
In addition, a study in the Czech Republic found that cold spells were associated with increased mortality from ischemic heart disease (IHD).[xxxii] The excess mortality, due to IHD, was most pronounced in the younger age group (0-64 years), and there were larger increases in the number of heart attacks than the number of deaths, due to chronic heart disease.
Abnormal skin responses to cold usually occur when subjects are exposed to moderate cold (0 to 15 ºC) for prolonged periods.[xxxiii] Chilblains are caused by repeated exposure of skin to temperatures from just above freezing, to as high as 15 °C (60 °F)[xxxiv]. The cold causes damage to the small blood vessels in the skin. Damage is permanent, and symptoms, such as redness and itching return with further exposure. It typically occurs on the cheers, ears, fingers and toes. There may also be blistering, inflammation and ulceration in severe cases.
Cold urticaria is a hypersensitive reaction to cold, which presents with hives or wheals, either during exposure to cold, or when the skin is warming up after exposure. Other symptoms, such as headache, vertigo, dyspnea or anaphylactic shock may also occur.
The HSE does not have specific guidance for working below 13 °C, though some British Standards offer advice in this area, and employers can demonstrate compliance by alternative means.[xxxv] The HSE advise that ‘when people are too cold’ employers can take steps, such as designing processes that minimise exposure to cold areas and cold products where possible, providing appropriate protective clothing for cold environments, introducing systems to limit exposure (e.g. flexible working patterns and job rotation), and providing sufficient breaks for employees to have hot drinks and warm up.[xxxvi]
The United States National Institute of Occupational Safety and Health (NIOSH) offers recommendations for employers and workers.[xxxvii] Recommendations for employers include:
- Schedule maintenance and repair jobs in cold areas for warmer months;
- Schedule cold jobs for the warmer part of the day;
- Reduce the physical demands of workers;
- Use relief workers or assign extra workers for long, demanding jobs;
- Provide warm liquids to workers;
- Provide warm areas for use during break periods;
- Monitor workers who are at risk of cold stress; and
- Provide cold stress training that includes information about: worker risk, prevention, symptoms, the importance of monitoring oneself and co-workers, treatment, and personal protective equipment.
Recommendations for workers include:
- Wear appropriate clothing: wear several layers of loose clothing as layering provides better insulation; avoid tight clothing as it reduced blood circulation;
- Make sure to protect the ears, face, hands and feet in extremely cold weather: boots should be waterproof and insulated; wear a hat;
- Move into warm locations during work breaks;
- Limit the amount of time outside on extremely cold days;
- Carry cold weather gear, such as extra socks, gloves, hats, jackets, blankets, a change of clothes and a thermos of hot liquid;
- Include a thermometer and chemical heat packs in your first aid kit;
- Avoid touching cold metal surfaces with bare skin; and
- Monitor your physical condition and that of your coworkers.
The CCOHS provides detailed information about clothing, footwear and face and eye protection, along with advice about other aspects of work in cold.[xxxviii] They also provide a useful summary of the health concerns and recommendations for preventative action in the following table:
Source: Canadian Centre for Occupational Health and Safety: OSH Answers Fact Sheets
Employers have general duties to ensure health and safety under the Health and Safety at Work Act 1974 to assess and control risks from work under the Management of Health, Safety, and Welfare Regulations (MHSWR). These legal requirements cover working outside, in the cold.
The Approved Code of Practice (ACoP) states that the temperature should provide reasonable comfort, without the need for special clothing and where this is not possible, due to hot or cold processes, or access to the outside environment, all reasonable steps should be taken to achieve a temperature as close as possible to ‘comfortable’. However, where maintaining these standards would be impractical, as a result of food, or other processes or products, needing to be kept cold, or rooms needing to be open to the outside; employers should apply the following measures as appropriate: enclosing or insulating the product (e.g. localised refrigerated enclosures including hoppers or conveyers); pre-chilling the product; keeping chilled areas as small as possible; exposing the product to workroom temperatures as briefly as possible; insulating with duckboards or other floor coverings, where workers have to stand for long periods (unless special footwear is provided which prevents discomfort); and undertaking draught exclusion using baffles and self-closing doors. Additionally, suitable protective clothing and rest facilities should be provided where local heating or cooling does not supply reasonable comfort. Where practical, systems of work, such as task rotation, should ensure that any individual worker is only exposed to an uncomfortable temperature for a limited period of time.
In relation to PPE, worn by employees, the Personal Protective Equipment (PPE) at Work Regulations require employers to consider the work environment, which includes the weather, if the work is outside. So, adequate protective clothing should be provided where exposure to cold is unavoidable and presents a hazard. However, when the body is forced to work, the production of heat rises. To maintain a balance between heat production and heat loss, insulation must decrease. Well-designed cold weather clothing allows the wearer to remove layers, or open vents and let the excess heat escape. This prevents overheating, and also chilling, which can be a serious problem in the cold. Sweat can accumulate in poorly designed clothing and continues to evaporate during periods of rest, making the body cold.
Many of the cases that deal with injuries sustained in extreme cold, are for the injury known as Non Freezing Cold Injury, or NFCI. NFCI occur when tissue fluids do not freeze [which usually occurs at around (-)0.5°C], but local temperatures remain low for several hours, or days. It can lead to life-long cold sensitivity and chronic pain. This condition is often seen in the hands, or feet, and is typically found in soldiers, sharing similarities with ‘trench foot’, suffered by soldiers in WWI. It has been suggested by some in the medical profession that soldiers from hot countries, such as those in the Commonwealth, are particularly sensitive to NFCI.[xxxix]
In edition 127 (here) we discussed the decision in Billett v Ministry of Defence  EWCA Civ 773, in which the Ministry of Defence appealed against a decision awarding damages, after it had admitted liability in respect of a NFCI sustained by the claimant. The claimant was employed by the Ministry as a lance corporal and whilst undertaking a field exercise whereby he was required to live outdoors in freezing cold weather and snow for six days, he suffered a NFCI to his feet, due to unsatisfactory footwear, provided to him by the army. The claimant continued to suffer symptoms in cold weather, even after his employment with the army ceased. These included:
- Burning sensations in hands and feet, painful in cold weather;
- Pins and needles in feet;
- Swollen and painful joints;
- Unable to gauge temperature with feet;
- Reduced sensation in feet;
- Cold hands and feet with poor circulation;
- Fear of cold conditions.
The claimant’s principal financial claim related to loss of future earning capacity and it was accepted that if the claimant lost his current job, he would have been at a disadvantage in finding new employment by consequence of the injury. This was accepted by both parties’ medical experts who stated:
‘We agree that Mr Billett:
Has a disadvantage on the labour market for some occupations due to his injuries. He will have to avoid jobs that require him to work outside and therefore will be more limited in terms of choice’.
The judge, at first instance, accepted that the claimant had sustained minor NFCI to his feet and that he suffered ongoing symptoms, as a result including being permanently sensitised to cold and experiencing pain in his feet. When determining quantum, he found that the claimant was ‘disabled’ according to the term defined in paragraph 35 of the Explanatory Notes to the Ogden Tables, but, only just. As such, the correct basis for assessing the claimant’s loss of future earning capacity was deemed to be through the use of Ogden Tables A and B, rather than a Smith v Manchester award (this was discussed in detail in edition 127). Thus, the claimant was awarded a total of £99,062.04 for loss of future earning capacity and £12,500 for PSLA. The defendant appealed and one of the grounds for this was that the claimant was not ‘disabled’ within the definition set out in the Ogden Tables.
Lord Justice Jackson, handing down judgment in the Court of Appeal, addressed the issue of disability at paragraphs 81-92. Specifically, at para 89, he stated that: ‘the focus of the inquiry should be upon what he [the claimant] cannot do as a result of the injury to his feet’. He went on to state at paragraphs 91 and 92 that:
‘The judge concluded that the claimant’s NFCI had a substantial adverse effect on his ability to carry out normal activities. In view of the factual evidence which the claimant and Ms Knight gave and which the judge accepted, he was entitled to reach that conclusion. The judge’s overall conclusion on the disability issue at para  of the judgement was:
“His condition qualifies as a disability…but only just”.
The judge was entitled to reach that conclusion. I therefore reject Mr Browne’s first argument’.
Notwithstanding this conclusion, LJ Jackson did reduce the award for loss of future earning capacity to £45,000, based on a different adoption of the Ogden tables.
A similar injury was seen in the case of Patterson v Ministry of Defence  EWHC 2767 (QB), in which the claimant originated from the Caribbean Island of St Vincent and served in the army in Iraq. During this period, he was deployed to Norway for cold weather survival training, which included learning to ski cross-country and downhill, including at night, and building a snow hole in temperatures of approximately minus 20 °C. As a result, he suffered a burning pain in his feet and sustained an NFCI injury. He was discharged from the army and subsequently brought a claim against the Ministry of Defence, claiming that his injury was caused by the Ministry's negligence, or breach of statutory duty. The claim was settled by payment of £75,000 in respect of damages and an agreed order that the Ministry should pay the costs of the claim. It was at this stage that there became a dispute as to whether the injury was a disease. Mr Justice Males, sitting in the High Court, held, at paragraph 48:
‘Thus NFCI is not caused or contributed to by any virus, bacteria, noxious agent or parasite. It is simply a case where blood fails to reach the cells in the nerves, skin and muscle of the claimant's feet as result of exposure to weather or environmental conditions. Although it involves no trauma in the sense of the direct application of force to the body, the mechanism is essentially the same as occurs in a case of trauma such as when a tourniquet is applied to a limb or a victim is stabbed. The result is damage or injury to the body parts affected, but this cannot be regarded as a “disease”. I accept the defendant's submission that if NCFI is a “disease”, so too are such conditions as chilblains, hypothermia, frostbite, sunstroke, sunburn and heat blisters which are no more than the result of exposure to weather conditions, and that this would be stretching the meaning of “disease” to surprising lengths which cannot have been intended. I accept also that it is significant that nowhere in Dr Roberts' detailed report on NFCI is there any suggestion that it constitutes a disease. While none of these factors is determinative by itself, together they amount to a compelling and in my judgment correct case that NFCI is not a “disease”’.
Cold injuries are not seen in the armed forces in isolation, but, as we have highlighted earlier in this feature, pose a risk to many occupations. A useful illustration of this can be found in Mr D Bragg v Gilbert Foods  WL 34910386, in which the applicant (this was a claim brought in the employment tribunal) worked 10 hour days with tasks involving the removal of frozen meat from a vat full of ice-cold water. No gloves were provided for this task by the defendant. This was an operation that was carried out every 10 or 15 minutes and, as a result of the repeated dipping into the cold water, their fingers and hands became numb. The Tribunal was satisfied, on the balance of probabilities, that the applicant complained to his supervisor from January 1996 onwards about the failure to provide gloves, despite requesting that gloves be made available and also made complaints on three or four occasions in 1996 to a partner in the respondents' undertaking. The respondents failed to do so, notwithstanding the requests that were made by the applicant and other employees. The respondents contended that suitable gloves were offered free of charge, but the Tribunal found, as a fact, that such gloves were not available, either on a paid basis, or free of charge. The applicant thereafter became ill with pneumonia, between 18 March and 8 April, and when he returned to his place of work, the working conditions had worsened. He, once again, complained about the unsatisfactory employment conditions, i.e. the absence of glove protection, and, since he had not received occupational satisfaction, chose to resign.
The Personal Protective Equipment Regulations 1992, which applied to the respondents' premises from January 1993 onwards, required the respondents to provide the employees’ appropriate protective clothing and equipment free of charge. These provisions applied in situations where there was a change in temperature, or cold conditions, operated. The Tribunal was satisfied, having considered the Regulations, that the failure to provide equipment in cold conditions amounted to a breach of these Regulations.
Working in cold environments poses a risk of injury to several groups of employees, including those working in the construction, food and agricultural industries and the armed services. The type of injury suffered will depend upon how low the temperature reaches in any given environment, ranging from skin conditions, cardiovascular problems and respiratory diseases.
Whilst there is no legal limit on how low temperatures are allowed to reach in the workplace, Unison say that the ideal temperature for most occupations is 16 °C and the HSE says that workers are particularly at risk from cold when the ambient temperature is below 10 °C. Clearly, this is unavoidable in some occupations, but in these instances, employers should be aware of their obligations and provide the necessary PPE and other preventative measures, in line with their statutory duties.
If they do not, the case law, discussed in this feature, shows that there is a real risk of employers being held liable for any resulting injuries.
[iii] Risk Assessment for Cold Weather Work. Seton UK Available at: http://www.seton.co.uk/legislationwatch/article/risk-assessment-cold-weather-work/ (Accessed: 11th May 2017)
[iv] Weather statistics for London. yr.no Available at: https://www.yr.no/place/United_Kingdom/England/London (Accessed: 11th May 2017)
[v] Met Office. UK climate. Available at: http://www.metoffice.gov.uk/public/weather/climate/ (Accessed: 11th May 2017)
[vi] Met Office, Cold weather and your health. Met Office Available at: http://www.metoffice.gov.uk/health/yourhealth/cold-weather-and-health (Accessed: 11th May 2017)
[vii] Mäkinen, Tiina M., and Juhani Hassi. “Health Problems in Cold Work.” Industrial Health 47, no. 3 (July 2009): 207–20.
[viii] Adverse health effects of exposure to cold. (2017). Available at: http://www.euro.who.int/en/health-topics/noncommunicable-diseases/chronic-respiratory-diseases/news/news/2013/02/how-cold-weather-affects-health/adverse-health-effects-of-exposure-to-cold (Accessed: 11th May 2017)
[ix] Bang, Berit E., Lisbeth Aasmoe, Laila Aardal, Gerd Sissel Andorsen, Anne Kristin Bjørnbakk, Cathrine Egeness, Ingrid Espejord, and Eva Kramvik. “Feeling Cold at Work Increases the Risk of Symptoms from Muscles, Skin, and Airways in Seafood Industry Workers.” American Journal of Industrial Medicine 47, no. 1 (January 1, 2005): 65–71. doi:10.1002/ajim.20109.
[x] Jammes, Yves, Marie José Delvolgo-Gori, Monique Badier, Chantal Guillot, Ghislaine Gazazian, and Laurence Parlenti. “One-Year Occupational Exposure to a Cold Environment Alters Lung Function.” Archives of Environmental Health: An International Journal 57, no. 4 (July 1, 2002): 360–65. doi:10.1080/00039890209601422.
[xi] Vergès, Samuel, Patrice Flore, Marie-Philippe Rousseau Blanchi, and Bernard Wuyam. “A 10-Year Follow-up Study of Pulmonary Function in Symptomatic Elite Cross-Country Skiers – Athletes and Bronchial Dysfunctions.” Scandinavian Journal of Medicine & Science in Sports 14, no. 6 (December 1, 2004): 381–87. doi:10.1111/j.1600-0838.2004.00383.x.
[xii] Kotaniemi, Jyrki-Tapani, Jari Latvala, Bo Lundbäck, Anssi Sovijärvi, Juhani Hassi, and Kjell Larsson. “Does Living in a Cold Climate or Recreational Skiing Increase the Risk for Obstructive Respiratory Diseases or Symptoms?” International Journal of Circumpolar Health 62, no. 2 (May 2003): 142–57.
[xiii] Mäkinen, Tiina M., and Juhani Hassi. “Health Problems in Cold Work.” Industrial Health 47, no. 3 (July 2009): 207–20.
[xiv] HSE, Work-related respiratory disease in Great Britain 2016 http://www.hse.gov.uk/statistics/causdis/respiratory-diseases.pdf (Accessed 11th May 2017)
[xv] Pienimäki, T. “Cold Exposure and Musculoskeletal Disorders and Diseases. A Review.” International Journal of Circumpolar Health 61, no. 2 (2002 2002): 173–82.
[xvi] Sormunen, Erja, Jouko Remes, Juhani Hassi, Tuomo Pienimäki, and Hannu Rintamäki. “Factors Associated with Self-Estimated Work Ability and Musculoskeletal Symptoms among Male and Female Workers in Cooled Food-Processing Facilities.” Industrial Health 47, no. 3 (2009): 271–82. doi:10.2486/indhealth.47.271.
[xvii] Aasmoe, Lisbeth, Berit Bang, Cathrine Egeness, and Maja-Lisa Løchen. “Musculoskeletal Symptoms among Seafood Production Workers in North Norway.” Occupational Medicine 58, no. 1 (January 1, 2008): 64–70. doi:10.1093/occmed/kqm136.
[xviii] Yagev, Yaron, Mark Gringolds, Isabella Karakis, and Rafael S. Carel. “Carpal Tunnel Syndrome: Under-Recognition of Occupational Risk Factors by Clinicians.” Industrial Health 45, no. 6 (2007): 820–22. doi:10.2486/indhealth.45.820.
[xix] Chiang, HC, SS Chen, HS Yu, and YC Ko. “The Occurrence of Carpal Tunnel Syndrome in Frozen Food Factory Employees.” Gaoxiong Yi Xue Ke Xue Za Zhi = The Kaohsiung Journal of Medical Sciences 6, no. 2 (1990 1990): 73–80.
[xx] Oksa, Juha, Michel B. Ducharme, and Hannu Rintamäki. “Combined Effect of Repetitive Work and Cold on Muscle Function and Fatigue.” Journal of Applied Physiology 92, no. 1 (January 1, 2002): 354–61.
[xxi] Kurppa, Kari, Eira Viikari-Juntura, Eeva Kuosma, Matti Huuskonen, and Pertti Kivi. “Incidence of Tenosynovitis or Peritendinitis and Epicondylitis in a Meat-Processing Factory.” Scandinavian Journal of Work, Environment & Health 17, no. 1 (1991): 32–37.
[xxii] Piedrahı́ta, Hugo, Laura Punnett, and Houshang Shahnavaz. “Musculoskeletal Symptoms in Cold Exposed and Non-Cold Exposed Workers.” International Journal of Industrial Ergonomics 34, no. 4 (October 2004): 271–78. doi:10.1016/j.ergon.2004.04.008.
[xxiii] Pope, D. P., P. R. Croft, C. M. Pritchard, A. J. Silman, and G. J. Macfarlane. “Occupational Factors Related to Shoulder Pain and Disability.” Occupational and Environmental Medicine 54, no. 5 (May 1, 1997): 316–21. doi:10.1136/oem.54.5.316.
[xxiv] Hildebrandt, V. H., P. M. Bongers, F. J. H. van Dijk, H. C. G. Kemper, and J. Dul. “The Influence of Climatic Factors on Non-Specific Back and Neck-Shoulder Disease.” Ergonomics 45, no. 1 (January 1, 2002): 32–48. doi:10.1080/00140130110110629.
[xxv] Mäkinen, Tiina M., and Juhani Hassi. “Health Problems in Cold Work.” Industrial Health 47, no. 3 (July 2009): 207–20.
[xxvi] Burström, Lage, Bengt Järvholm, Tohr Nilsson, and Jens Wahlström. “Back and Neck Pain due to Working in a Cold Environment: A Cross-Sectional Study of Male Construction Workers.” International Archives of Occupational and Environmental Health 86, no. 7 (October 1, 2013): 809–13. doi:10.1007/s00420-012-0818-9.
[xxvii] HSE Health Surveillance - Guidance for Occupational Health Professionals http://www.hse.gov.uk/vibration/hav/advicetoemployers/havocchealth.pdf (Accessed 20 December 2016)
[xxviii] Minami, J., Y. Kawano, T. Ishimitsu, H. Yoshimi, and S. Takishita. “Seasonal Variations in Office, Home and 24 H Ambulatory Blood Pressure in Patients with Essential Hypertension.” Journal of Hypertension 14, no. 12 (December 1996): 1421–25.
[xxix] Brennan, P. J., G. Greenberg, W. E. Miall, and S. G. Thompson. “Seasonal Variation in Arterial Blood Pressure.” Br Med J (Clin Res Ed) 285, no. 6346 (October 2, 1982): 919–23. doi:10.1136/bmj.285.6346.919.
[xxx] Kim, Joon-Youn, Kap-Yeol Jung, Young-Seoub Hong, Jung-Il Kim, Tae-Won Jang, and Jung-Man Kim. “The Relationship between Cold Exposure and Hypertension.” Journal of Occupational Health 45, no. 5 (2003): 300–306. doi:10.1539/joh.45.300.
[xxxi] Sartini, C. et al. Effect of cold spells and their modifiers on cardiovascular disease events: Evidence from two prospective studies. Int J Cardiol 218, 275–283 (2016). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4917887/ (Accessed 11th May 2017)
[xxxii] Davídkovová, H., Plavcová, E., Kynčl, J. & Kyselý, J. Impacts of hot and cold spells differ for acute and chronic ischaemic heart diseases. BMC Public Health 14, 480 (2014).
[xxxiii] Page, Elizabeth Heller, and Neil H. Shear. “Temperature-Dependent Skin Disorders.” Journal of the American Academy of Dermatology 18, no. 5, Part 1 (May 1988): 1003–19. doi:10.1016/S0190-9622(88)70098-5.
[xxxiv] NIOSH Cold stress - Cold related illnesses https://www.cdc.gov/niosh/topics/coldstress/coldrelatedillnesses.html (Accessed 20 December 2016)
[xxxvi] HSE, Managing workplace temperature http://www.hse.gov.uk/temperature/thermal/managers.htm (Accessed 20 December 2016)
[xxxvii] CDC - NIOSH Workplace Safety and Health Topic - Cold Stress - Recommendations. Available at: https://www.cdc.gov/niosh/topics/coldstress/recommendations.html (Accessed: 11th May 2017)