Q&A: I run a health/care facility. How can I protect staff from heat strain and heat-related illness?

Updated: 22 May 2020

Answer

The prevention and management of heat-related illness often requires education, peer-to-peer support and formal protocols.

Appropriate strategies depend primarily on the environmental conditions within facilities and the acclimatization and fitness of staff.11 If entire facilities can be cooled safely, this is very effective, but is often unfeasible or insufficient, with the result that other measures are needed. As heat stress is produced through exertion as well as exposure to hot conditions, decisions on what activities staff undertake and how shifts and rotations are managed is also crucial.

Wearing PPE increases heat stress, but other conditions that also put health workers at higher risk of heat-related illnesses, include: working in hot ambulatory care services, field hospitals or other temporary facilities that are not adequately cooled; working long shifts with limited breaks or insufficient time to recover before returning to work; and having limited access or opportunity to consume fluids to stay hydrated.

What can be done?

Heat stress awareness and pre-heat season preparation

  • Brief staff on the symptoms of heat-related illnesses, the extra heat burden experienced from wearing PPE, and other environmental and individual risk factors.
  • Reinforce messaging with posters on heat stress symptoms and responses.
  • Encourage staff to “stay healthy”, hydrate, and maintain a basic level of aerobic fitness.
  • Encourage heat acclimatization planning and use progressive exposure to improve thermal tolerance.

Awareness of hot weather conditions

  • Provide information on local weather conditions and forecasts as well as associated risk, particularly when conditions change. Note that in hot and humid environments, smaller fluctuations can be more significant (e.g., the heat index, or “how hot it feels”, may be greater).
  • Monitor workers for signs and symptoms of heat-related illness
  • Create a ‘buddy’ system for informal peer-to-peer monitoring of heat stress, following a protocol that is appropriate to your context.
  • In conditions conducive to heat stress, avoid situations where staff work alone.
  • Supervisors are also responsible for monitoring staff for the signs and symptoms of heat stress.

Limit exposure and/or exertion

  • Consider needed staffing levels to enable surge/shadow rotations to facilitate break and rest periods.
  • Schedule work that may result in the rapid storage of body heat and/or increase body core temperature as manageable periods of time. Follow this with exposure to cooler areas to dissipate body heat and reduce the risk of heat stress. This could involve directing staff through hot and cool areas, or to tasks and wards requiring different levels of PPE.
  • Work/rest cycles are an established approach but may not always be practicable. These can be complemented by informal, more responsive measures (such as the ‘buddy’ system or self-pacing).
  • Mechanical aids (e.g. trolleys) can also help to reduce physical workloads and, as a result, the body’s metabolic heat production.

Establish a cool rest area

  • Orovide a cool area for staff and schedule adequate time for cooling during rest breaks.
  • Ensure air conditioning and ventilation systems are regularly inspected and maintained, and operate at the correct settings. Consider the potential risks of infection before using air-conditioning or fans. See Q&A on air-conditioning and ventilation.
  • In many places, electric fans may be more accessible; but may help transmit the virus indoors, and in very hot and dry environments these can increase heat stress.12
  • Consider supplementing with ice slurry consumption where cooling facilities are not available or are insufficient, particularly in hot and humid conditions. This requires safe and hygienic provision of a blender, water and ice. It is recommended these are housed in a “clean” area, disinfected on a routine basis, with the exterior of the blender sanitized after each use.
  • Consider the use of cooling devices under protective garments such as a vest with phase change materials, ice or equivalent.

Hydration/nutrition

  • Provide cool water and access to food within clean (and ideally cool) areas.
  • Encourage staff to self-monitor their hydration. Practical options include: displaying simple urine-colour charts in toilet facilities; and providing weighing scales in changing rooms so that staff can weigh themselves before and after each shift to calculate fluctuations in their body mass (and therefore hydration level).

Toilet facilities

  • Providing toilet facilities within hot areas means that staff are less likely to reduce their intake of fluid to avoid urinating until they can reach a toilet outside the hot area. This reduces their risk of dehydration through the combined effects of heat and a lack of fluids.

Formal monitoring

  • Encourage workers to report heat stress symptoms.
  • Consider issuing a brief anonymous staff survey to monitor heat stress symptoms and the adequacy of control strategies.
  • Create a critical incident log to record heat illness and “near misses”. This can inform future policies as well as the training of new staff.

Treatment area for heat-related illness, including heat stroke

  • Provide access to cooling facilities for staff to rapidly reverse excessively high body core temperature.
  • Where immersion in cool water is not practicable, apply cold towels and/or ice packs to the body.

Evidence

Ensure staff have the necessary knowledge to identify signs and symptoms, and prevent heat stress5 as well as the ability to respond to these practically with simple protocols considering the potential risks of infection. Hydration also supports thermal regulation6 and should be included in education materials. Basic self-monitoring of dehydration can be supported by providing urine-colour charts and pre- and post-shift body mass assessments.7

In the workplace, a ‘buddy’ system is a well-established way of providing non-disruptive health and safety monitoring8. Brief, anonymous staff surveys allow monitoring of heat-stress rates and can help identify ways to improve mitigation measures.9 Staffing schedules are also potential heat management tools. Work/rest cycles are well-established approaches to this.1 Guiding staff to a cool area to dissipate heat is crucial10 and can be combined with break times.

Body core temperature tolerance is improved considerably in people with high – rather than medium – levels of aerobic fitness.1 Aerobic fitness is also a key factor in limiting the age-related decline in heat tolerance.2 It has also been demonstrated that heat acclimatization plays a key role in supporting medical responders exposed to heat (and humidity) to work more effectively and can be enabled through progressive heat acclimatization guidelines.4  

References

  1. McLellan, T. M., Daanen, H. A. & Cheung, S. S. 2013. Encapsulated environment. Comprehensive Physiology, 3, 1363-1391.
  2. Meade, R. D., Notley, S. R. & Kenny, G. P. 2019. Aging and human heat dissipation during exercise-heat stress: An update and future directions. Current Opinion in Physiology, 219-225.
  3. Brearley, M. B., Norton, I. N. & Trewin, A. S. 2017. The Case for Heat Acclimatization of Disaster Responders—An Australian perspective. Frontiers in public health, 5, 98.
  4. Brearley, M. 2016. Pre-deployment Heat Acclimatization Guidelines for Disaster Responders. Prehospital and Disaster Medicine, 31, 85-9.
  5. Jackson, L. L. & Rosenberg, H. R. 2010. Preventing heat-related illness among agricultural workers. Journal of agromedicine, 15, 200-215.
  6. Alhadad, S. B., TAN, P. M. & LEE, J. K. 2019. Efficacy of heat mitigation strategies on core temperature and endurance exercise: a meta-analysis. Frontiers in physiology, 10.
  7. Cheuvront, S. & Kenefick, R. 2014. Dehydration: physiology, assessment, and performance effects. Compr Physiol 4: 257–285.
  8. Bernard, T. E. 1999. Heat stress and protective clothing: an emerging approach from the United States. Annals of occupational hygiene, 43, 321-327.
  9. Carter, S., Oppermann, E., Field, E. & Brearley, M. 2020. The impact of perceived heat stress symptoms on work-related tasks and social factors: A cross-sectional survey of Australia's Monsoonal North. Applied Ergonomics, 82, 102918.
  10. Hostler, D., Reis, S. E., Bednez, J. C., Kerin, S. & Suyama, J. 2010. Comparison of active cooling devices with passive cooling for rehabilitation of firefighters performing exercise in thermal protective clothing: a report from the Fireground Rehab Evaluation (FIRE) trial. Prehospital emergency care, 14, 300-309.
  11. Cheung, S., Lee, J. K. W. & Oksa, J. 2016. Thermal stress, human performance and physical employment standards. Applied Physiology, Nutrition, and Metabolism, 41, 6.
  12. Morris, N. B., English, T., Hospers, L., Capon, A. & Jay, O. 2019. The Effects of Electric Fan Use Under Differing Resting Heat Index Conditions: A Clinical Trial. Annals of internal medicine, 171, 675-677.