Weekly Safety Meeting – Working in Hot Environments

Millions of U.S. workers are exposed to heat in their workplaces. Although illness from exposure to heat is preventable, every year thousands become sick from occupational heat exposure; and some cases are fatal. Most outdoor fatalities, 50% to 70%, occur in the first few days of working in warm or hot environments because the body needs to build a tolerance to the heat gradually over time. The process of building tolerance is called “heat acclimatization.” Lack of acclimatization represents a major risk factor for fatal outcomes.

As temperatures begin to rise, so does the risk of heat illness. Heat-related deaths and illness are preventable, yet many people succumb to the effects.

Heat-related illness is also an underlying cause of a high percentage of non-fatal incidents.

People suffer from heat-related illness when their bodies are unable to compensate and properly cool themselves. The body normally cools itself by sweating. Under certain conditions, sweating will fail to cool the body and the storage of heat over time will lead to the signs and symptoms of heat illness.

Your best defense against heat-related illness is prevention. Staying cool and making simple changes in fluid intake, activities, and clothing during hot weather can help you to remain safe and healthy.

Heat Illness Prevention:

Minimize Heat – Probably one of the best ways to avoid heat stress is to minimize the heat in the workplace. However, this can be especially difficult when the workplace itself is outdoors and little or no shade is available to help reduce exposure.

Gradual Adjustment – The best way to prepare the body for heat is through gradual adjustment. This adjustment usually takes from 5-7 days, during which the body will undergo a series of changes that will make continued exposure to heat more endurable.

Gradual Exposure – Gradual exposure to heat gives the body time to become acclimatized to higher environmental temperatures. Heat-related illness is more likely to occur among workers who have not been given ample time to adjust to working in the heat.

Preventive Measures:

As the heat index begins to climb to dangerous levels, precautions must be taken to avoid the possibility of a heat-related illness. Staying indoors in air-conditioned areas should be considered whenever possible.

Should It Be Necessary to Go Outside for Prolonged Periods During Peak Temperatures:

  • Limit the amount of time spent in the heat until fully acclimatized.
  • Properly hydrate your body by drinking more fluids before, during, and after exposure to heat.
  • Don’t wait until you’re thirsty to drink.
  • Don’t drink liquids that contain alcohol, caffeine, or large amounts of sugar – they cause your body to lose more fluid.
  • Avoid very cold drinks – cool (50°-60°) fluid is ideal.
  • Eat light meals – avoid hot and heavy meals.
  • Wear lightweight, light-colored, loose-fitting clothing.
  • Take frequent rest breaks in a cool shaded area. Protect yourself from the sun by wearing a wide-brimmed hat and use sunscreen of SPF 15 or higher.
  • Avoid overexertion – slow down and avoid strenuous activity.
  • Become familiar with the early warning signs and symptoms of the various heat-related illnesses.


The Importance of Drinking Water:

  • During a day’s work in the heat, a person may produce as much as 2 to 3 gallons of sweat. It is important that water intake during the workday be about equal to the amount of sweat produced.
  • Don’t depend on thirst to signal when and how much to drink.
  • Workers should drink 3 to 4 cups of water every hour starting at the beginning of the shift.



Hot summer months pose special hazards for workers. Labor-intense activities in hot weather can raise body temperatures beyond the level that normally can be cooled by sweating. Heat illness initially may manifest itself as heat rash or heat cramps but can quickly escalate to heat exhaustion and then heat stroke if simple preventative measures are not followed.

Download flyer: SMOTW_729_Working in Hot Environments

Download Spanish flyer: SMOTW_729_Working in Hot Environments_esp

You may also like...