Exposure to extreme heat or working in a hot environment indoors or outdoors puts a toll on the human body. When combined with strenuous physical activities, humidity, poor hydration practices, or personal health factors (such as medications, illness, pre-existing medical conditions, or being overweight), that toll can quickly lead to a serious injury or fatality from a heat-related illness (HRI). HRIs occur when the body becomes unable to properly cool, resulting in a rapid rise in body temperature, or hyperthermia. HRIs include heat rash, heat cramps, heat syncope (fainting), rhabdomyolysis (death of muscle fiber), heat exhaustion or heat stroke.
While HRIs present a direct health concern, the physical symptoms of heat stress also elevate risk factors that can lead a worker to suffer other acute, traumatic injuries. These symptoms include a loss of balance, reduced mental awareness/focus, loss of grip, a decrease in reaction time, and general fatigue/muscle weakness. These physical states not only put the worker at risk, but possibly fellow co-workers and the public. Managing heat-related risk, whether from work outdoors or inside, is an essential part of an overall safety plan to prevent work-related injuries.
Keeping workers safe from excess heat stress is 100% possible. Use these tips to manage the impact of heat stress and to keep workers cool while working in hot environments.
- Evaluate forecasted conditions against physical work demands to develop a daily work plan to safely manage heat stress.
- Monitor the temperature and humidity throughout the day such as by using the free NIOSH/OSHA Heat Safety Tool App (see screen image at right), to adjust the work plan as needed.
- Have pre-work meetings to discuss HRI symptoms, expected heat-related conditions, and safety measures.
- Establish an acclimatization plan to allow new and returning workers to adapt to working in a hot environment.
- Identify at-risk environmental factors, such as the sun, air temperature, humidity, radiant heat from machinery, and air movement.
- Discuss non-environmental factors that contribute to heat stress. Physical characteristics such as body weight, nutrition, medical conditions, and age are factors to consider.
- Avoid foods or drinks that contribute to dehydration like caffeine, sugary drinks, and alcohol.
- Provide water and breaks on a regular schedule and locate water stations near work areas.
- Sports drinks and other electrolyte-based drinks can help combat dehydration.
- Wet towels or ice are simple but effective measures to combat the stress of heat.
- Wear clothing that is lightweight and breathable.
- Limit the wearing time for heavy or waterproof garments that retain heat and increase the likelihood of heat stress.
- Provide areas where employees can escape the heat and cool down. Shaded areas with fans are useful to reduce heat stress.
- Have an emergency plan and inform the employees of the policy.
Managing heat stress is part of a good risk management strategy and is a requirement of providing a workplace free of recognized safety hazards. In developing an effective heat stress management plan, be sure to check current state and federal regulations to ensure you are including any required elements.
- Heat Illness Prevention Campaign
- OSHA-NIOSH Heat Safety Tool – A free App that offers site specific heat index information and risk assessment.
- Center for Disease Control (CDC) Topic Page on Heat Stress
- OSHA Topic Page on Heat Stress
- NIOSH – Occupational Exposure to Heat and Hot Environments
- National Integrated Heat Health Information System