If you work outdoors or are exposed to extreme heat you could be at risk for heat stress. Everybody can handle a little stress, but too much stress, in regards to heated working environments, can quickly turn into much more serious conditions such as, heat stroke, heat exhaustion, heat cramps, rashes, and dehydration. Prevention of heat stress in workers is important. Recognition of potential elevated temperatures in the working environment is the responsibility of both employer and employee.
It doesn’t have to be really hot outside for heat stress to occur. Losing the opportunity to periodically cool down, rehydrate and rest allows the body’s temperature to keep rising. A person can get heat stress even when working in 70 degree weather. Air circulation, hydration, and frequent rest periods (or lack of all three) have the ability to amplify or diminish heat related symptoms. Employers should provide training to workers so they understand what heat stress is, how it affects their health and safety, and how it can be prevented.
Each year organizations like OSHA, and CDC publish warnings and potential health risks regarding the upcoming seasons. Below is the annual refresher on heat stress types and management provided by the CDC. Stay cool!
Heat Stroke
Heat stroke is the most serious heat-related disorder. It occurs when the body becomes unable to control its temperature: the body’s temperature rises rapidly, the sweating mechanism fails, and the body is unable to cool down. Heat stroke can cause death or permanent disability if emergency treatment is not given.
Symptoms
- Symptoms of heat stroke include:
- Hot, dry skin or profuse sweating
- Hallucinations
- Chills
- Throbbing headache
- High body temperature
- Confusion/dizziness
- Slurred speech
First Aid
- Take the following steps to treat a worker with heat stroke:
- Call 911 and notify their supervisor
- Move the sick worker to a cool shaded area
- Cool the worker using methods such as:
- Soaking their clothes with water, spraying, sponging, or showering them with water
- Fanning their body
Heat Exhaustion
Heat exhaustion is the body’s response to an excessive loss of the water and salt, usually through excessive sweating. Workers most prone to heat exhaustion are those that are elderly, have high blood pressure, and those working in a hot environment.
Symptoms
- Symptoms of heat exhaustion include:
- Heavy sweating
- Extreme weakness or fatigue
- Dizziness, confusion
- Nausea
- Clammy, moist skin
- Pale or flushed complexion
- Muscle cramps
- Slightly elevated body temperature
- Fast and shallow breathing
First Aid
- Treat a worker suffering from heat exhaustion with the following:
- Have them rest in a cool, shaded or air-conditioned area
- Have them drink plenty of water or other cool, nonalcoholic beverages
- Have them take a cool shower, bath, or sponge bath
Heat Syncope
Heat syncope is a fainting (syncope) episode or dizziness that usually occurs with prolonged standing or sudden rising from a sitting or lying position. Factors that may contribute to heat syncope include dehydration and lack of acclimatization.
Symptoms
- Symptoms of heat syncope include:
- Light-headedness
- Dizziness
- Fainting
First Aid
- Workers with heat syncope should
- Sit or lie down in a cool place when they begin to feel symptoms
- Slowly drink water, clear juice, or a sports beverage
Heat Cramps
Heat cramps usually affect workers who sweat a lot during strenuous activity. This sweating depletes the body’s salt and moisture levels. Low salt levels in muscles causes painful cramps. Heat cramps may also be a symptom of heat exhaustion.
Symptoms
- Muscle pain or spasms usually in the abdomen, arms, or legs.
First Aid
- Workers with heat cramps should:
- Stop all activity, and sit in a cool place
- Drink clear juice or a sports beverage
- Do not return to strenuous work for a few hours after the cramps subside because further exertion may lead to heat exhaustion or heat stroke
- Seek medical attention if any of the following apply:
- The worker has heart problems.
- The worker is on a low-sodium diet
- The cramps do not subside within one hour
Heat Rash
Heat rash is a skin irritation caused by excessive sweating during hot, humid weather.
Symptoms
- Symptoms of heat rash include:
- Heat rash looks like a red cluster of pimples or small blisters
- It is more likely to occur on the neck and upper chest, in the groin, under the breasts, and in elbow creases
First Aid
- Workers experiencing heat rash should:
- Try to work in a cooler, less humid environment when possible
- Keep the affected area dry
- Dusting powder may be used to increase comfort
Recommendations for Employers
- Employers should take the following steps to protect workers from heat stress:
- Schedule maintenance and repair jobs in hot areas for cooler months
- Schedule hot jobs for the cooler part of the day
- Acclimatize workers by exposing them for progressively longer periods to hot work environments
- Reduce the physical demands of workers
- Use relief workers or assign extra workers for physically demanding jobs
- Provide cool water or liquids to workers. Avoid alcohol, and drinks with large amounts of caffeine or sugar
- Provide rest periods with water breaks
- Provide cool areas for use during break periods
- Monitor workers who are at risk of heat stress
- Provide heat stress training that includes information about:
- Worker risk
- Prevention
- Symptoms
- The importance of monitoring yourself and coworkers for symptoms
- Treatment
- Personal protective equipment
Recommendations for Workers
Workers should avoid exposure to extreme heat, sun exposure, and high humidity when possible. When these exposures cannot be avoided, workers should take the following steps to prevent heat stress:
- Wear light-colored, loose-fitting, breathable clothing such as cotton
- Avoid non-breathing synthetic clothing
- Gradually build up to heavy work
- Schedule heavy work during the coolest parts of day
- Take more breaks in extreme heat and humidity
- Take breaks in the shade or a cool area when possible
- Drink water frequently. Drink enough water that you never become thirsty. Approximately 1 cup every 15-20 minutes
- Avoid alcohol, and drinks with large amounts of caffeine or sugar
- Be aware that protective clothing or personal protective equipment may increase the risk of heat stress
- Monitor your physical condition and that of your coworkers
You’ve provided a good and timely review, Bob. For those looking to get a handle on raising awareness and getting some preliminary data to support additional investigation or policies, an agency of the Ontario government (OHCOW) produced a simplified version of considerations based on the “Humidex” value commonly reported by Canadian weather forecasters:
While it’s not as rigorous nor considered a replacement for the ACGIH WBGT process, it is easily adapted to daily conditions and relatively inexpensive to monitor. A summary is available on the OHCOW website at:
http://www.ohcow.on.ca/uploads/Home/Humidex%20Heat%20Stress%20Response%20Plan%20Chart%20Revised.pdf