Working in Excessive Heat

With some of the hottest days of summer ahead, it is a perfect time to review the hazards of working in the heat. This is especially relevant to those required to wear a chemical protective suit exposing them to a significantly higher risk of heat stress.

Understanding Excessive Heat

Excessive heat is typically defined as a combination of high ambient temperatures and high humidity levels, often measured using the Heat Index or Wet Bulb Globe Temperature (WBGT). When the body is exposed to extreme heat, it struggles to regulate its core temperature, leading to heat stress, heat exhaustion, and in severe cases, heat stroke. These conditions can impair cognitive function, physical performance, and overall safety.

Chemical Protective Suits

Drivers required to wear a chemical protective suit are exposed to a significantly higher risk of heat stress. Chemical protective suits are constructed from materials that are impervious to chemicals, but this protection comes at the cost of the body’s evaporative cooling ability. The heavy materials of the suit prevent heat dissipation, trap heat and moisture, restrict movement, and increase physical effort, and can lead to severe heat buildup with prolonged use.

Heat Stress and Heat Related Illnesses

Workers exposed to extreme heat or who work for long periods in hot environments may be at risk of heat stress. Prolonged heat stress can result in heat rashes, heat exhaustion, heat cramps, or, in the worst cases, heat stroke or rhabdomyolysis. Those who are 65 years of age or older, are overweight, have heart disease or high blood pressure, or take medications that may be affected by extreme heat are at higher risk to heat related illnesses.

Heat Exhaustion is the body’s response to an excessive loss of water and salt, usually through excessive sweating, normally accompanied by a core temperature of 104⁰F or greater.

Symptoms of heat exhaustion include:

• Headache
• Nausea
• Dizziness
• Weakness
• Irritability
• Thirst
• Heavy sweating
• Elevated body temperature
• Decreased urine output

First Aid

Treat a worker who has heat exhaustion by doing the following:

• Take worker to a clinic or emergency room for medical evaluation and treatment.
• Call 911 if medical care is unavailable.
• Remove the worker from the hot area and replenish liquids and electrolytes.
• Remove unnecessary clothing, including shoes and socks.
• Cool the worker’s head, face, and neck with cold water or ice packs.
• Encourage frequent sips of cool water or sports drinks.
• Have someone stay with the worker until help arrives.

Heat Stroke occurs when the body can no longer control its temperature. The body’s temperature rises rapidly, the sweating mechanism for evaporative cooling fails, and the body is unable to cool itself. When heat stroke occurs, the body temperature can rise to upwards of 106⁰F within 10 to 15 minutes. Heat stroke can cause permanent disability or death if the person does not receive emergency treatment.

Symptoms of heat stroke include:

• Confusion, slurred speech, seizures
• Loss of consciousness (coma)
• Hot, dry skin or profuse sweating
• Very high body temperature

First Aid

Immediately take the following steps to treat a person suspected to have heat stroke:

• Call 911
• Move the worker to a shaded, cool area and remove outer clothing.
• Cool the worker quickly with cold water, a cold or ice bath, if possible.
• Circulate air around them to speed the cooling process.
• Place cold, wet towels or ice packs on the head, neck, armpits, and groin or soak the clothing with cool water.
• Stay with the worker until emergency medical services arrive.

Having covered the most dangerous and most common of the heat related illnesses, follow these links for more information on symptoms and first aid for heat rash, syncope, rhabdomyolysis, and other dangers of heat stress:

• https://www.cdc.gov/niosh/topics/heatstress
• https://www.cdc.gov/niosh/topics/heatstress/heatrelillness.html

Prevention Strategies

The industrial safety equipment industry has made advancements in cooling solutions like vests and neck wraps that can be readily sourced online.

• Polar Products
• Industrial Safety Gear – Summer Safety Products

Here are some recommended strategies to reduce heat stress:

Pre-Work

• Acclimatization: Gradually increase exposure to heat over 1-2 weeks to improve tolerance.
• Health Screenings: Assess your fitness and identify your tolerance of excessive heat and risk of heat stress.
• Training: Educate yourself to recognize the symptoms of heat stress and learn the recommended preventive measures to mitigate them.

During Work

• Work/Rest Cycles: Implement regular breaks in cool areas to allow the body to recover.
• Hydration: Ensure access to water and drink regularly. Electrolyte-replenishing drinks can help maintain balance.
• Cooling Technologies: Use cooling vests, wraps, and other gear to help dissipate body heat and cool the bloodstream.

Post-Work Recovery

• Cool-down Procedures: Remove unnecessary gear and clothing and rest in a shaded or air-conditioned area for recovery.
• Re-hydrate: Replenish your body’s fluids and electrolytes in the days following heat stress.

Future Directions and Innovations

Advances in materials science are paving the way for more breathable work gear and chemical protective suits without compromising safety. Innovations like integrated cooling systems and smart sensors that provide real-time data on workers' conditions are becoming more accessible. Ongoing research continues to explore new methods to balance safety with effective heat stress management.

Conclusion

Balancing the need to get the job done and the crushing summer heat can be a challenge, but by recognizing the risks, weather, and your own physical conditioning, you can do it safely.