Heat Stress

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People exposed to extreme heat or work in hot environments may be at risk of heat stress. Heat stress can result in heat stroke, heat exhaustion, heat cramps, or heat rashes. Heat can also increase the risk of injuries in workers as it may result in slippery fingers, poor visibility from foggy safety glasses, and dizziness.

Those who are at greater risk for heat stress include outdoor workers and workers in hot environments such as underground and above ground miners, construction workers, farmers, boiler room workers, factory workers, etc. If you are older or overweight, have heart disease or high blood pressure, or take medications that may be affected by extreme heat, you are at a much higher risk.

Factors that lead to heat-related health problems at work include:

• Inadequate cooling off or rest periods
• Insufficient water consumption
• Climatic conditions (such as low air movement, high humidity levels and high air temperature)
• Inappropriate clothing
• Individual factors that may cause dehydration (such as poor diet, vomiting, diarrhoea or alcohol and caffeine consumption)
• Individual medical conditions that may cause heat stress (such as heart problems, diabetes or hypertension)
• Individual medication that may affect the body's temperature regulation
• An individual's age, general physical fitness and weight.
• Environmental factors

Environment and seasonal factors that can contribute to heat problems include:

• High air temperatures
• Higher relative humidity levels
• Low air movement
• Radiant heat from plant (dryer, oven, furnace) or processes such as smelting, molten metals
• Radiant heat from working outdoors in the sun.

HEAT RELATED ILLNESSES

Heat stress can affect individuals in different ways, and some people are more susceptible to it than others either because of an illness or medication that may encourage the early onset of heat stress.

Heat related illness can occur when the body is unable to cool itself adequately and body temperature rises. This can be associated with different effects ranging from mild heat rash or cramps through to heat exhaustion or the more severe and potentially fatal heat stroke.

Heat Stoke
Heat stroke is the most serious heat illness. 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. When heat stroke occurs, the body temperature can rise to 41 °C or higher within 10 to 15 minutes. Heat stroke can cause death or permanent disability if emergency treatment is not given.

Symptoms Include:

• Hot, dry skin or profuse sweating
• Hallucinations
• Chills
• Throbbing headache
• High body temperature
• Confusion/dizziness
• Slurred speech

First Aid:

• Call your paramedic or medical officer if on site or call an ambulance.
• Move the person to a cool area.
• Cool the worker using methods like:
• 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 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 person 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 acclimatisation.

Symptoms Include:

• Light-headedness
• Dizziness
• Fainting

First Aid:

• Sit or lie down in a cool place when you begin to feel symptoms.
• Sip water, clear juice, or a sports beverage.

Heat Cramps
Heat cramps usually affect workers who sweat a lot during strenuous activity, or are just big sweaters in general. This sweating depletes the body’s electrolyte and water levels, causing painful cramps. Heat cramps may also be a symptom of heat exhaustion.

Symptoms Include:

•  Muscle pain or spasms usually in the abdomen, arms or legs.

First Aid:

• 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 as 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 don’t subside within 1 hour

Heat Rash
Heat rash is a skin irritation caused by excessive sweating during hot, humid weather.

Symptoms 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:

• Try to work in a cooler, less humid environment when possible.
• Try to get the lightest PPE appropriate for the role.
• Keep the affected area dry.
• Talcum powder may be used to increase comfort.