Environmental, Health and Safety

Heat Stress

Who is affected?

Workers exposed to hot and humid conditions are at risk of heat stress, especially those doing heavy work tasks or using bulky protective clothing and equipment. The risk is greater if workers have not built up a tolerance to hot conditions, are in poor physical condition, are older, or if they have heart disease, high blood pressure, or are taking certain medications.

What is heat stress?

The body normally cools itself by sweating. During hot weather, especially with high humidity, sweating is not enough. Body temperature can rise to dangerous levels if precautions are not taken. Heat stresses range from heat rash and heat cramps to heat exhaustion and heat stroke. Heat stroke can result in death and requires immediate medical attention.

How can heat stress be prevented?

Remember three simple words:
      water,
      rest,
      shade.
Drinking water often, taking breaks, and limiting time in the heat can help prevent heat stress.

Gradually build up to heavy work in hot conditions.
Allow more frequent breaks during the first week of work and for workers who have been away from work for a week or more.
Know and look out for the symptoms of heat stress in yourself and others during hot weather.
Plan for an emergency and know what to do. Acting quickly can save lives!

Training and other resources

Use these fact sheets, training materials, and posters to prevent heat stress for your workers.

Supervisor's Daily Checklist

Training posters:

Health effects of heat agriculture
Health effects of heat construction
Water. Rest. Shade. Fact sheet

Training video & other materials:


This video shows how to prevent and respond to heat stress with water, rest, and shade. It features workers from agriculture, construction, and landscaping.
Discussion guide to use with video.
OSHA training guide with three 15-minute lessons
Dangers of heat stress from Farm Safety Association
Agricultural Tailgate Safety Heat Stress Training
Heat Stress awareness from Texas Workers' Comp

Contact Information

Albert Moore, Industrial Hygienist and Laser Safety Officer

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