Heat Stress
Heat stress is defined as the inability of the body to rid itself of excess heat as the result of working in a hot environment, especially when humidity levels are high. Every year, millions of employees are exposed to heat in their workplaces; indoors and outdoors. Heat exposures generally occur in construction and agriculture work, but also at many general industry worksites. With the proper procedures implemented, heat illness from exposure to heat can be preventable.
Employer Responsibilities
Create a Heat Illness Prevention Plan
- Have a plan prepared for your specific type of heat exposures.
- Recognize heat hazards within the workplace.
- Acclimatize new workers.
- Use engineering controls, work practices and personal protective equipment.
- Provide training to workers on heat stress.
- Designated employee that oversees heat safety.
Educate Your Workers
- Familiar with the types of heat-related illnesses and their signs and symptoms.
- Understanding their job-related and personal risk factors.
- Importance of providing first aid treatment immediately for heat-related illness.
- When to use emergency numbers for heat-related illness.
- Reporting procedures for heat-related illness.
- Drinking plenty of liquids and importance of taking rest breaks.
Supervision and Monitoring
- Able to identify, reduce and control heat hazards through engineering controls and work practices.
- Provide oversight on a daily basis during summer months or where heat hazards exist.
- Recognize early symptoms of heat stress and knowledge of first aid treatment, including when to activate emergency medical services.
- Calculate heat stress and respond to heat advisories and warnings.
Prevention Measures
Engineering Controls
- Increasing general ventilation.
- Providing local ventilation provided at the source of heat.
- Adding air conditioning or using cooling fans.
- Use of misting fans with fine water spray.
- Reflective shields for radiant heat sources.
- Insulating hot sources such as furnace walls.
- Elimination of steam leaks.
Personal Protective Equipment
- Use of thermally conditioned clothing such as vests with cooling ice packs
- Wearing reflective clothing or insulated suits.
- Using face shields that reflect infrared.
- Use of cooling neck wraps or towels.
- Implementing engineering and work practice controls to eliminate the need for PPE.
Work Practice Controls
- Providing plenty of fluids.
- Allowing shorter shifts.
- Frequent, short breaks in cooler areas such as shaded or air conditioned areas.
- Rotating job functions between heavy and light.
- Alternate work hours such as late afternoons or evenings.
- Use of a buddy system.
- Designated heat monitor.
- Provide training on first aid and emergency procedures.
Best Practices
- Establish a written site-specific heat illness prevention plan.
- Conduct initial and periodic refresher training on heat stress signs and symptoms, first aid and emergency procedures.
- Provide a dedicated heat stress monitor for each site.
- Implement procedures for acclimating workers.
- Utilize engineering and work practice controls.
Worker Personal Risk Factors
- Medications such as antihistamines, diuretics, and blood pressure medications.
- Physical characteristics such as unacclimated, age, and physically unfit.
- Health conditions such as being a diabetic, overweight, having high blood pressure.
- Behavioral characteristics such as alcohol or illicit drug use, and low intake of water.
Work-Related Risk Factors
- Heavy physical activity such as lifting, climbing, and digging.
- Environmental conditions such as temperature, humidity, air speed and radiant heat.
- Unacclimated workers especially during the first few days.
- Clothing that holds in body heat such as coveralls and protective clothing.
- Presence of heat sources such as furnaces, fires and hot tar.
- Reflective material such as metal and water.
Acclimating New Workers
- Schedule workers to shorter amounts of time in the hot environment.
- Allow frequent rest breaks.
- Train new workers about heat stress, symptoms and protective measures.
- Use of buddy system so no one works alone.
- Monitor workers closely during first few days.
- Follow "Rule of 20 Percent" for building heat tolerance.
Employee Responsibilities
- Drink plenty of fluids, especially water and sports drinks.
- Recognize the signs and symptoms of heat-related illnesses.
- Know first aid treatment and emergency procedures.
- Report signs and symptoms of heat-related illnesses.
- Take frequent rest breaks in cooler areas.
- Use the buddy system.