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Heat Stress

The hot summer months are upon us again, and with that comes the potential for heat-related disorders. If you don’t think this is an important topic, think again. Heat is the #1 weather-related killer in the United States according to the National Weather Service.

The Cooling Machine

The human body effectively maintains our core temperatures at 98.6 degrees. On hot days, especially while working, our body’s ability to maintain this ideal core
temperature can become stressed. When the weather turns hot and humid, this mix can severely compromise our body’s normal cooling mechanism.

Four environmental factors affect the amount of stress a worker faces in a hot work area: temperature, humidity, radiant heat (such as from the sun or a furnace), and wind speed. Individuals with high blood pressure or heart conditions and people who take diuretics (water pills) may be more sensitive to heat exposure.

The body defends itself from heat through three mechanisms: breathing, sweating, and changing the blood flow. The first reaction is to circulate blood to the skin, which increases skin temperature and allows the body to give off some heat. During heavy work, muscles need more blood flow, which reduces the amount of blood available to flow to the skin and to release the heat.

Sweating also helps the body to cool off, but only when the humidity levels are low enough to allow the sweat to evaporate and if water and salts lost through sweating are replaced.

Recognize the Symptoms

There are three levels of heat-related disorders: heat stress, heat exhaustion, and heat stroke. Prevention begins with recognizing initial symptoms. Symptoms
include dizziness, headache, nausea, weakness, blurred vision, poor posture,
increased heart rate, hand tremors, profuse sweating, fainting, muscle cramps and, in extreme cases, coma. Workers exhibiting any of these symptoms should be moved to a cool area immediately and allowed to rest and rehydrate. If symptoms persist, medical attention should be sought.

Keep It Cool

Heat-related disorders can be prevented with some simple steps. Important steps include engineering controls, such as air conditioning and ventilation; making the work environment cooler; and work practices, such as work/rest cycles, scheduled water breaks, and work-hardening periods which allow workers to build up a level of tolerance to working in the heat. It is crucial to instruct employees in appropriate attire and to provide sunscreen.

Employers should include these prevention steps in their training and jobsite
planning. It’s important to be aware of the symptoms of heat-related illness in yourself and others during hot weather. Plan for an emergency and know what to do. Acting quickly can save lives!

Additional Resources:

Hyperthermia Defined

Types of Heat Stress (Hyperthermia)
Heat Stroke | Heat Exhaustion | Heat Syncope | Heat Cramps | Heat Rash

Preventative Steps

Paul Sleeter, ARM
Loss Control Representative

Call Toll-Free 1-800-322-0160