Nationwide, we’re experiencing hotter, longer and more frequent extreme heat events. Extreme heat is the leading cause of weather-related deaths in the U.S., according to the National Weather Service.

Heat can be dangerous for anyone, but some face greater risks. Outdoor workers face increased threat of heat stress due to hot temperatures, high humidity, intense radiation from full sunlight or limited access to air circulation or cooling. Those at risk include lineworkers, first responders, farmers, construction workers and landscapers.

People working indoors without air conditioning or near heat sources such as in kitchens, factories or foundries also face greater risks of heat-related illness.

While we can’t control the weather, we can understand the hazards of heat stress and take precautions to ensure safety when temperatures and humidity are on the rise. 

Understanding heat stress

Heat stress occurs when the body cannot adequately cool itself through sweating. This can result from a combination of high temperatures, humidity, physical exertion and a lack of hydration. When the body overheats, it can lead to various heat-related illnesses, ranging from mild heat cramps to life-threatening heatstroke.

Personal risk factors

Certain factors can increase an individual’s susceptibility to heat stress, including:

• Age and health: Older workers and those with preexisting health conditions are at greater risk.
• Hydration levels: Dehydration can impair the body’s ability to cool itself.
• Acclimatization: Workers who are not accustomed to hot conditions are more prone to heat stress.
• Clothing: Wearing heavy or nonbreathable clothing can restrict heat dissipation.

Effects of heat exposure on health

Heat cramps:

• Symptoms: Muscle pain or spasms, usually in the arms, legs or abdomen.
• Response: Rest in a cool place, hydrate with electrolyte-rich fluids and gently stretch the affected muscles.

Heat exhaustion

• Symptoms: Heavy sweating, fatigue, nausea, dizziness, irritability, pale/cool skin and a rapid, weak pulse.
• Response: The condition is usually due to loss of water and salt from excessive sweating. Move to a cooler area, loosen clothing, sip water slowly and apply cold compresses or cool water to the skin. Seek medical attention if symptoms persist.

Heat stroke

• Symptoms: High body temperature, throbbing headache, hot/dry skin, confusion, slurred speech, rapid and strong pulse, and possible loss of consciousness.
• Response: Heat stroke can be fatal, as it restricts the body’s ability to cool itself. Call 911 immediately. While waiting for medical help, move to a cooler environment, and lower body temperature with cool water or ice compresses. Remove any unnecessary clothing.

Preventing heat stress

Prevention is key to protecting workers from heat stress. Here are some essential tips:

• Hydrate frequently. If you wait until you’re thirsty, you’ve waited too long. You should drink water every 15-20 minutes. Consider adding electrolytes, and avoid caffeinated or sugary beverages and heavy, hot meals.
• Take frequent breaks. Schedule breaks in shaded, air-conditioned or cooler areas.
• Acclimatize and gradually increase heat exposure. Allow new or returning employees time to adjust.
• Adjust work schedules. Plan heavy activities for cooler parts of the day and gradually increase workloads to help workers acclimate to the heat.
• Wear appropriate clothing. Opt for lightweight, loose-fitting and light-colored clothing. While necessary for safety, be aware that personal protective gear can increase body heat.
• Wear sun protection, including a hat and sunglasses. Apply sunscreen regularly.
• Know the signs and watch out for each other. Ensure all workers are aware of the risks, symptoms and treatments for heat stress.

OSHA’s Heat Illness Prevention guide at www.osha.gov/heat offers resources for employers and workers about heat hazard awareness and prevention to keep workers safe. You can also download OSHA’s Heat Safety App at www.osha.gov/heat/heat-app to calculate the heat index for a worksite and get reminders about protective measures that should be taken at that risk level to protect workers.

By understanding the dangers of extreme heat and implementing proactive measures, outdoor workers can significantly reduce the risk of heat stress. Staying informed, hydrated and vigilant can make all the difference in maintaining health and safety on the job.