Heat Exhaustion

Heat exhaustion can develop quickly when you work in hot, humid weather. Your body overheats and raises your core body temperature from 37° to 40° Celsius or 98.6° to 104° Fahrenheit.

What causes heat exhaustion?

• Exposure to hot weather or working conditions (like in a furnace or an area with steam pipes).
• People with medical conditions like diabetes, heart disease, or skin diseases and rashes may be more susceptible to heat.
• Loss of water and salt from heavy sweating.
• Clothing that traps heat and doesn't 'breathe'.

What are the signs of heat exhaustion?

Heat exhaustion victims may not recognize they have the symptoms below. Watch your fellow co-workers for the following signs:

• Cool, pale clammy skin
• Heavy sweating
• Dizziness or fainting
• Headache
• Fatigue
• Nausea
• Vomiting
• Muscle aches / heat cramps
• Intense thirst
• Very high body temperature, over 40° Celsius or 104° Fahrenheit.

How can you avoid heat exhaustion?

• Acclimatize yourself to working in hot conditions if you've been away from work or are just starting a new job.
• If possible, move tasks indoors or into the shade.
• Stay out of the sun between 11 a.m. and 3 p.m.
• Drink plenty of water (about 1 litre every hour).
• Avoid drinks with caffeine or alcohol which can dehydrate you.
• Wear a hat, sunglasses and loose-fitting protective clothing. 
• Take a cool shower or bath.
• Apply sunscreen regularly.
• Sprinkle water on skin or keep a damp cloth on back of neck.

Sources:
Canadian Centre for Occupational Health & Safety
British National Health Service
Environment Canada
Mayo Clinic
Merck & Co. Inc