Even though heat-related deaths and illnesses are preventable, the Centers for Disease Control and Prevention says that an average of 658 people die from exposure to extreme heat every year. Thousands more become ill while working in high temperatures or humid conditions, according to the Occupational Safety and Health Administration.

Under OSHA law, employers are responsible for providing workplaces free of known safety hazards, which includes extreme heat. A range of heat-induced illnesses – from cramps to the potentially fatal heat stroke – can affect anyone, regardless of age or physical condition.

How Heat Harms

When the air temperature is close to or warmer than normal body temperature, which ranges from 97 to 99 degrees Fahrenheit in most people, it is difficult for the body to cool itself. Blood circulated to the skin retains heat, so sweating becomes the main way the body cools off. But sweating is effective only if the humidity level is low enough to allow evaporation, and if people replace the fluids and salts they lose.

A person’s core temperature and heart rate increase if the body cannot release excess heat. As the body continues to store heat, the person loses the ability to concentrate, has difficulty focusing, may become irritable or sick and often loses the desire to drink. Ultimately, fainting or even death can occur if the person is not cooled down.

Exposure to heat also increases the risk of injuries due to such factors as sweaty palms, fogged-up safety glasses, dizziness and burns from hot surfaces or steam.

Protecting Workers

Employers whose workers are exposed to high temperatures have a legal, moral and fiscal obligation to protect them. Take these steps to prevent heat stress and keep both workers and bottom lines healthy:

• Provide water, rest and shade. OSHA encourages employers to provide cool, easily accessible drinking water (not beverages with caffeine, which are dehydrating), and encourage workers to drink about one cup every 15 minutes. Frequent breaks in shaded areas also should be mandatory for employees working in extreme heat.
• Allow workers to acclimatize by gradually increasing the length of time they work over a two-week period so they can build a tolerance to the heat.
• Schedule heavy work during the coolest time of the day, if possible.
• Suggest workers wear lightweight, light-colored clothing.
• Rotate employees when working in the heat is unavoidable.
• Use air conditioning and ventilation to cool indoor work environments.
• Train staff to recognize the signs of heat-related illnesses and take care of people in distress.

Heat stress symptoms include:

• Headaches, dizziness, lightheadedness, fainting
• Clammy skin
• Irritability or confusion
• Upset stomach, vomiting

Heat stroke symptoms include:

• Dry, hot skin with no sweating
• Confusion, loss of consciousness
• Seizures or convulsions

If employers or employees notice any of these signs in themselves or co-workers, they should:

• Call 911
• Move the worker to shade
• Wipe the skin with cool water
• Loosen clothing
• Fan the worker with cardboard or other material

Remember that heat-related illnesses can be prevented. Employers should reduce heat exposure and associated risks through air conditioning to cool indoor workspaces, and should implement work practices that require frequent breaks, drinking water often and providing an opportunity for workers to build up tolerance to working in the heat.

Know and watch for symptoms of heat-related illness during hot weather. Plan what to do in an emergency, because quick action can save lives.