Blog Post #19 – Protection in the Workplace from Excessive Heat

Excerpt from the OH&S Canada magazine

A landscaper collapsed and died at the end of the day of mowing, weeding and using a backpack blower. Emergency medical assistance was called, but the man was pronounced dead at the hospital. His body temperature was 107 degrees F or 42 degrees C.

A seventeen year old boy was working in a cornfield as a summer job. He never wore a hat and the temperature was heading beyond 100 degrees F. or 37.78 degrees C. One minute he was chatting with co-workers, the next, he was nowhere to be found. He collapsed from heat stroke and was attended to. He also ended up being sent back home, which was 3 hours away, and never did finish his work assignment. His ego got in the way and it cost him his job. His employer, however, should have made it mandatory that protective headwear be worn.

Heat kills workers, both outdoors and in hot, humid conditions indoors. Any workplace can be too hot for safety. Even mild heat illness causes distractions or lightheadedness, leading to mistakes and injuries.

The hazardous health effects include:
1) Heat Fatigue — Victims tire quickly, leading to mental confusion and mistakes, making jobs more dangerous;
2) Heat Cramps — These painful cramps happen when workers lose too much salt through sweating;
3) Heat Exhaustion — Symptoms include headache, nausea, dizziness, weakness and thirst. Victims may faint or behave irrationally; and
4) Heat Stroke — It occurs when body temperatures reach 105 degrees F. or 41 degrees C. Symptoms include hot dry skin, headache, nausea, confusion, convulsions, and unconsciousness.

To prevent heat illness:
1) Acclimatize — It takes a week or two of adjustment to handle heavy work in hot conditions. Aggravating factors include poor physical condition, obesity, age, medication and alcohol use;
2) Dress Down — Wear light, loose-fitting clothes that permit air circulation. Be sure, also, that your clothing won’t get tangled in moving machinery;
3) Conserve Energy — Save heavy jobs for the coolest part of the day;
4) Seek Shelter — Take rest breaks in a cool area. Make use of protective equipment such as sunshades, ventilation, fans and air conditioning;
5) Drink — Make sure to drink cool water frequently. Five ounces or 150 ml every twenty minutes is about right; and
6) Add Salt — Replace the salt you lose through sweating. A sprinkling on your lunch is enough. Check with your doctor if you need to limit your salt intake.

For treatment for yourself or a work buddy for any signs of heat illness take no chances.

For heat stroke:
1) Call for medical help right away;
2) Move him/her to a cooler place;
3) Maintain his/her airway and breathing;
4) Lie him/her down and remove outer clothing; and
5) Apply cool water via spray or a wet blanket.

Wet Bulb Globe Temperature is a very important tool to measure heat stress. The Wet Bulb Globe Temperature (WBGT) is a composite temperature used to estimate the effect of temperature, humidity, wind speed (wind chill) and solar radiation on humans. It is used by industrial hygienists, athletes, and the military to determine appropriate exposure levels to high temperatures. Look up the WBGT on the appropriate website to aid in developing your company’s heat stress policy.

The American Conference of Governmental Industrial Hygienists publishes threshold limit values (TLVs) that have been adopted by many governments for use in the workplace. The process for determining the WBGT is also described in ISO 7243, Hot Environments – Estimation of the Heat Stress on Working Man, Based on the WBGT Index

Remember — In Ontario, “ALL Accidents are Preventable”

‘Work’ and ‘Play’ safe.

Daniel L. Beal
CHSEP – Foundation Level
VP & Senior Trainer
HRS Group Inc.