When the body heats up faster than it can cool itself, mild to severe illness may develop. Air temperature, humidity, and clothing can increase the risk of developing heat-related illness. So can age, sex, weight, physical fitness, nutrition, alcohol or drug use, or pre-existing diseases like diabetes. 

It’s important to recognize the symptoms of heat-related illness and understand how to prevent, control, and respond to it.

  • Drink water – Drink small amounts of water frequently, about a cup every 15-20 minutes. The importance of doing this cannot be overstated. In some heat related deaths, water was available but workers did not drink it.
  • Limit exposure time and/or temperature – Try to schedule hot jobs for cooler times of the day or cooler seasons of the year. Take rest breaks in cool areas. Add more workers to reduce workload or reduce the workday.

Take time to acclimate

Workers are at greatest risk with the sudden onset of heat. Gradually adapting to heat will reduce the severity of heat stress.

  • Implement engineering controls – Mechanize heavy jobs or increase air movement with fans or coolers.
  • Wear loose, lightweight clothing – Clothing can affect heat buildup.
  • Avoid using salt tablets – Taking salt tablets can raise blood pressure, cause stomach ulcers, and seriously affect workers with heart disease.

Mild symptoms of heat-related illness

Someone with a mild reaction to heat may have a rash called “prickly heat” or painful muscle spasms, called heat cramps, during or after activity. A mild reaction may also include fatigue or dizziness. You may notice a change in physical or mental performance and an increase in accidents. A person with a moderate reaction or heat exhaustion, will have some or all of the following symptoms: excessive sweating, cold, moist, pale or flushed skin, thirst, extreme weakness or fatigue, headache, nausea, lack of appetite, rapid weak pulse, or giddiness. If not properly treated, the victim may collapse.

Move anyone with mild or moderate symptoms to a cool, shaded place with circulating air. Have them lie down and, if conscious, have them sip cool water at frequent intervals. If symptoms continue, a doctor should be called.

Severe symptoms of heat-related illness

In severe cases of heat illness, heat stroke may result. The victim’s face is flushed red and their skin is hot and dry with no sweating. They develop a severe headache with deep, rapid breathing, a very high fever, and may become delirious. They may become unconscious, have convulsions, or lapse into a coma. This condition is potentially fatal unless emergency medical treatment is obtained. Immediately call for medical help. In the meantime, get them out of the hot environment. Loosen clothing and pour water over the entire body. Get air circulating around the body.

Recognizing the warning signs and symptoms of heat-related illness and using preventive and control measures can reduce the frequency and severity of heat illness while increasing worker productivity.