Many workers spend hours each day in hot , humid weather conditions. Working in extreme heat can pose special health and safety hazards. By learning to recognize the signs of heat-related illnesses and taking steps to prevent them, you can keep your employees safe, comfortable and productive.

Types of heat-related illnesses

Heat exposure can affect worker health in a number of ways.

Heat stroke occurs when the body fails to regulate its own temperature. Symptoms include confusion, loss of consciousness, convulsions and hot, dry skin. Heat stroke can be fatal unless treated immediately. If you suspect someone is the victim of heat stroke, call for medical assistance, move them to a shady or cool area and provide drinking water as soon as possible.

Heat exhaustion happens when fluids or sodium chloride lost through sweating aren't adequately replenished. The victim continues to sweat while experiencing extreme weakness, fatigue, nausea or headache. If an individual shows signs of heat exhaustion, have them rest in a cool place and drink fluids. If vomiting or loss of consciousness occurs, seek medical assistance immediately.

Heat cramps or muscle spasms can occur when sodium chloride is lost through sweating and isn't replaced. Tired muscles are susceptible to cramps, which can be relieved by increasing fluid intake. If the cramps or spasms are severe, medical attention may be required.

Heat rash occurs in hot, humid environments when sweat doesn't evaporate effectively. In severe cases, heat rash can become so uncomfortable that it inhibits sleep and impedes worker performance. To prevent heat rash, rest in a cool place.

The extent of stress each individual feels from heat exposure will depend on age, fitness and other factors.

Preventing heat-related illnesses

People need time to adapt to a hot work environment. Begin heat exposure for short periods and gradually increase. Give new employees or workers returning from an absence time to adjust to the heat. Follow these tips to reduce the risk of heat-related illnesses:

• Provide plenty of drinking water in convenient, visible locations.
• Use power tools to reduce manual labor.
• Alternate work and rest periods in a cool area.
• Schedule intense work during the coolest part of the day whenever possible.
• Permit workers to stop and rest if they feel uncomfortable.
• Consider an individual's physical condition when determining their ability to work in hot weather conditions. People taking certain medications or with certain health conditions may be at greater risk.

It's important to educate employees about the need to drink plenty of fluids while working in a hot environment. Also, train all staff to recognize and treat heat-related illnesses. For more information, see the guide Occupational Heat Exposure from the U.S. Department of Labor.