TOP TIP: Keeping Your Cool – OSHA’s Heat Illness Prevention Suggestions for Employers


This summer has already seen heat records shatter across the U.S. The Occupational Safety and Health Administration has a Heat Illness Prevention campaign, which includes a website that collects resources on working in the heat. With regard to employers, OSHA offers extensive guidance, including the following points:

Create a Heat Illness Prevention Plan. OSHA recommends that employers with workers exposed to high temperature should develop a heat illness prevention program. Employers should consider these elements in creating a plan:

  • Who will provide oversight on a daily basis?
  • How will new workers gradually develop heat tolerance?
  • Temporary workers may be more susceptible to heat and require closer supervision.
  • Workers returning from extended leave (typically defined as more than two weeks) may also be at increased risk.
  • How will the employer ensure that first aid is adequate and the protocol for summoning medical assistance in situations beyond first-aid is effective?
  • What engineering controls and work practices will be used to reduce heat stress?
  • How will heat stress be measured?
  • How to respond when the National Weather Service issues a heat advisory or heat warning?
  • How will the employer determine if the total heat stress is hazardous?
  • What training will be provided to workers and supervisors?

Provide Day-to-Day Supervision. Employers should designate an individual at the worksite to monitor conditions and implement the plan, and provide training to that individual on how to:

  • identify and control heat hazards;
  • recognize early symptoms of heat stress;
  • administer first aid for heat-related illnesses; and
  • activate emergency medical services quickly when needed.

Protect New Workers. Employers should understand that workers new to the warm environment (whether newly hired, returning, or subject to changing conditions) may not be used to the heat loads and are at higher risk of heat-related illness. Such workers must be acclimated to the heat, by taking the following steps for a 1-2 week period:

  • Schedule new workers to work shorter amounts of time working in the heat, separated by breaks, in heat stress conditions.
  • Give new workers more frequent rest breaks.
  • Train new workers about heat stress, symptoms of heat-related illness, and the importance of rest and water.
  • Monitor new workers closely for any symptoms of heat-related illness.
  • Use a buddy system and don’t allow new workers to work alone.
  • If new workers talk about or show any symptoms, allow them to stop working. Initiate first aid. Never leave someone alone who is experiencing symptoms!

OSHA also recommends a “Rule of 20 percent” for building heat tolerance, involving shorter workdays that increase over the first 1-2 weeks. Thus, new workers should work only 20% of the normal duration on the first day, and increase by 20% on subsequent days until they reach the full duration.

Heat Hazard Recognition. Employers should recognize the factors that create occupational heat stress. These include:

  • environmental conditions (including outdoor/indoor work, direct sun/shade, wind, reflective materials, etc.)
  • heat sources in the work area (fires, ovens, hot equipment, etc.)
  • required clothing or protective gear
  • level of physical activity
  • individual risk factors

Engineering Controls. Employers may explore engineering controls to make the work environment cooler and reduce manual workload, including the following:

  • Air conditioning (including in crane or construction equipment cabs, break rooms)
  • Increased general ventilation
  • Cooling fans
  • Local exhaust ventilation at points of high heat production or moisture (such as exhaust hoods in laundry rooms)
  • Reflective shields to redirect radiant heat
  • Insulation of hot surfaces (such as furnace walls)
  • Elimination of steam leaks
  • Cooled seats or benches for rest breaks
  • Use of mechanical equipment to reduce manual work (such as conveyors and forklifts).
  • Misting fans that produce a spray of fine water droplets

Work Practices. Employers should also explore modified work practices, particularly where engineering controls are not effective:

  • Require mandatory rest breaks in a cooler environment (such as a shady location or an air conditioned building). The duration of the rest breaks should increase as heat stress rises. See the Hazard Recognition section for more information.
  • Consider scheduling work at a cooler time of day, such as early morning or late afternoon.
  • Reduce physical demands as much as possible by planning the work to minimize manual effort (such as delivering material to the point of use so that manual handling is minimized).
  • Rotate job functions among workers to help minimize exertion and heat exposure.
  • Ensure that workers drink an adequate amount of water or electrolyte-containing fluids.
  • Employers should have an emergency plan that specifies what to do if a worker has signs of heat-related illness, and ensures that medical services are available if needed.
  • Workers should watch out for each other for symptoms of heat-related illness and be prepared to administer appropriate first aid to anyone who is developing a heat-related illness.
  • Administer appropriate first aid to any worker who is developing a heat-related illness.
  • In some situations, employers may need to conduct physiological monitoring of workers.
  • Implement a buddy system for new workers and in heat stress environments.
  • Avoid drinking hot beverages during lunch and afternoon breaks.

Personal Protective Equipment. In some situations, special equipment or clothing may provide protection. These include insulated suits, reflective clothing, infrared reflecting face shields, cooling neck wraps, and cooling vests or jackets (utilizing compressed air or ice/cooling packs).

Hydration, Rest and Shade. Employers should provide these in a manner that is plentiful and readily accessible. OSHA suggests cool water for shorter jobs, and electrolyte-containing beverages (like sports drinks) for jobs over 2 hours.