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Hot under the collar: The signs and symptoms of heat stress

Heat stress impacts thousands of U.S. workers annually, with symptom severity ranging from uncomfortable rashes to internal temperatures so high they become fatal. It’s important to know the signs of each type of heat stress so that you can maintain a safe working environment no matter the weather.

Red, irritated bumps:

The first and most common sign of heat stress is a heat rash. Red bumps develop in patches across the body, typically in folds of skin where sweat can pool, like the neck, upper chest, groin, elbow creases and under the breasts. When these occur, keep the rash dry and apply powder to deal with any discomfort. It’s best to take a break and continue work in a cooler environment if possible. Since rashes can be an indicator of potentially more harmful heat stress symptoms, keep an eye on workers who are experiencing the condition to ensure it doesn’t escalate.


Heat cramps are also a common and relatively less serious form of heat stress. Symptoms include:
  • Muscle cramps and pain
  • Heavy sweating
  • Fatigue
  • Thirst
If someone around you is experiencing these symptoms, it’s best to move them to a cool, shaded space and have them sit and rest for a few hours before getting back to work. They should sip on cold water or sports drinks to avoid dehydration.

Identifying heat exhaustion and heat strokes:

Heat stress can be substantially more severe than just cramps or rashes, though. Heat exhaustion signs can include:
  • Sudden, intense headaches or nausea
  • Dizziness
  • Lack of alertness
  • Fainting or collapsing
  • Muscle cramps
  • Low blood pressure
  • Weak but rapid pulse
  • Cool and moist skin
If a worker experiences any of these symptoms, you should immediately move them out of the sun and into air conditioning or somewhere cool and shaded. They should rest and not return to work for the rest of the day. Give them a cold sports drink or cold water to drink, and use ice or cold water on their pulse points (wrists and neck) to cool their body down. If possible, place a fan in front of them. Heat strokes can look like heat exhaustion, but they also include symptoms like:
  • Confusion
  • Slurred speech
  • Very high body temperature (104 degrees, ranging up to even 106)
  • Seizures
  • Coma
If you suspect that an employee is experiencing a heat stroke, immediately call 911. While emergency medical services arrive, treat them as if they were experiencing heat exhaustion: shade, water and rest.

Preventing occupational heat stress:

Although complications that arise from a heat stroke may clear up within a few days with medical attention, the long-term impacts may persist for several months. Managers should avoid assigning roles that require employees to be outside or in heat for long periods of time to those who have previously experienced heat exhaustion or heat strokes. Generally, it’s important to be aware of the restraints of specific employees. A variety of factors can impact how susceptible individuals are to heat stress, from their age to their prescription medications. Some important steps in helping employees become accommodated to managing heat are:
  • Assigning consistent breaks in cool environments (preferably rooms with air conditioning)
  • Providing safe, clean and cold drinking water and encouraging consumption
  • Monitoring the daily heat index and assigning shifts according to the Work Rest Schedules
  • Supporting workers’ decisions to take breaks and rest when experiencing ay of the above symptoms
For more information on keeping you and your employees safe on the job, visit Mutual Benefit Group’s Safety Center to learn more.