Each year, millions of workers across the United States are exposed to high temperatures in their workplaces. While heat-related illnesses are entirely preventable, thousands of workers still suffer from them annually — and unfortunately, some cases result in death.
Understanding Heat Acclimatization
Studies show that 50% to 70% of outdoor heat-related fatalities occur within the first few days of working in warm or hot environments. This happens because the human body needs time to gradually adapt to higher temperatures — a process known as heat acclimatization.
Workers who are not acclimatized face a significantly higher risk of heat illness or death when exposed to sudden or extreme heat conditions.
Risk Factors for Heat Illness
Both occupational and personal factors can increase the likelihood of heat-related illnesses:
- Occupational Risk Factors:
- Performing intense physical labor
- Working in hot or humid environments
- Lack of acclimatization to heat
- Wearing heavy or non-breathable clothing that traps body heat
- Personal Risk Factors:
- Medical conditions (e.g., heart disease, diabetes, or obesity)
- Poor physical fitness or dehydration
- Previous episodes of heat illness
- Alcohol or drug use
- Certain medications that impair the body’s ability to regulate temperature
OSHA Regulations
Under the General Duty Clause, Section 5(a)(1) of the Occupational Safety and Health Act of 1970, employers are legally required to provide a workplace that is “free from recognized hazards” likely to cause death or serious physical harm.
This includes heat-related hazards, meaning employers must implement appropriate controls—such as rest breaks, hydration, shade, and acclimatization programs—to prevent heat illnesses and fatalities.