Keeping cool

Features - Safety Focus

Facility managers must address heat-related workplace risks.

May 8, 2014
Brenda Jacklitsch, MS

Heat and hot environments can affect both indoor and outdoor workers, resulting in illness and injury. According to the Bureau of Labor Statistics, 4,190 injury and illness cases arose from exposure to environmental heat that resulted in one or more days of lost work among private industry and state and local government workers in 2010.

Heat-related illnesses may include heat stroke, heat exhaustion, heat cramps and heat rash. These illnesses develop when the body becomes overheated through the combined contributions of metabolic heat (e.g., the internal heat we produce in proportion to work intensity), environmental factors (e.g., air temperature, humidity, etc.) and clothing or personal protective equipment. In addition to illnesses, injuries related to working in a hot environment may occur because of sweaty palms, fogged-up safety glasses, dizziness or contact with hot surfaces or steam.

It is important for facility managers to address heat-related risks and to provide workers with preventive measures so they can go home injury and illness-free.

The importance of training

Everyone can benefit from training, whether it is the person who has been working for five years or the new hire. Periodic training is warranted because high temperatures can result in heat stroke, which can be deadly.

Everyone (supervisors and workers) should be trained to recognize symptoms of a heat-related illness. These symptoms may include rashes, cramps, headaches, nausea, dizziness, weakness, elevated body temperature, decreased urine output, profuse sweating, loss of consciousness and seizures. Supervisors should be trained to periodically check on workers performing tasks in hot areas. In addition, workers should be trained not only to look out for their own health but they also should be monitoring their coworkers. Workers should be trained and encouraged to immediately report symptoms in themselves and others. During training it should be made clear that stopping because you feel unwell is acceptable and encouraged.

Taking time to acclimatize

Acclimatization consists of the natural changes that occur when someone has had long-term exposure to a hot environment. It may take one to two weeks for someone to acclimatize to a hot environment, but afterward they are usually able to sweat more efficiently and tend to have a more stable circulatory system. When someone is not allowed time to acclimatize, he or she may show signs of heat stress and experience difficulty replacing water that has been lost in sweat.

If someone is new to the job or has been away for more than a week, gradually increase his or her workload and provide more frequent breaks during his or her first couple of weeks on the job.

Encouraging breaks and hydration

Being well-hydrated is essential, even before a worker begins his or her shift. Heavy sweating during a shift can mean the worker is experiencing a large loss in water and electrolytes, resulting in problems with how his or her body regulates extra heat. Drinking 8 ounces of water or other fluids every 15 to 20 minutes while performing moderate activities in moderate conditions should be encouraged. Supervisors should remind workers to take hydration breaks.

Cool water should be readily available in a convenient, visible location close to the work area. If workers are in conditions where they are sweating for several hours, sports drinks containing balanced electrolytes should be provided. In addition, your company may want to implement a fluid replacement table that has more specific guidelines that consider the temperature, level of work and the work/rest schedule.

Work/rest schedules take into account the air temperature, the type of clothing and personal protective equipment worn and whether the work is considered light, moderate or heavy.

Providing a cool area for workers to take a rest and water break also is highly recommended.

Additional recommendations

Recyclers should consider these additional recommendations, whether their operations are indoors, outdoors or both.

For indoor operations:

  • Install air conditioning or increase ventilation (if cooler air is available from the outside).
  • Reduce temperatures through the use of reflective shields to redirect radiant heat, insulate hot surfaces and decrease water vapor pressure (e.g., seal steam leaks, keep floors dry).
  • Use fans to increase air speed, unless the air temperature is higher than the skin temperature.
  • If high ambient temperatures typically occur, seek a professional consultation.

For outdoor operations:

  • Monitor weather reports daily.
  • Reschedule jobs with high heat exposure to cooler times of the day.
  • When possible, schedule routine maintenance and repair projects for the cooler seasons of the year.


More information

The National Institute for Occupational Safety and Health (NIOSH) is currently updating the “Criteria for a Recommended Standard: Occupational Exposure to Heat and Hot Environments.” This draft document is available online and provides examples of indoor and outdoor case studies and information on a variety of topics, including hydration and fluid replacement, physiological monitoring, acclimatization, work/rest schedules and heat-related illnesses. The content of this technical document may be best suited for a supervisor or safety manager wanting to address heat exposure at his or her operation; however, some of the content also could easily be shared during worker training. To view the draft NIOSH criteria document, visit

Other NIOSH educational materials include:

  • “OSHA-NIOSH Infosheet: Protecting Workers from Heat Illness,”, a three-page PDF co-branded (with OSHA). This is a great resource for managers and safety professionals to review and utilize during training;
  • “NIOSH Fast Facts: Protecting Yourself from Heat Stress,”, includes symptoms and first aid for heat-related illnesses.
  • “NIOSH Workplace Safety and Health Topics: Heat Stress,”, which provides heat stress information, all related NIOSH publications and some other useful resources.


Brenda Jacklitsch, MS, is a health scientist at the National Institute for Occupational Safety and Health in the education and information division. She is updating the “Criteria for a Recommended Standard: Occupational Exposure to Heat and Hot Environments.”