Blog Post #1401 – Heat-Stress Warning Released in Manitoba

Excerpt from the OH&S Canada magazine (July 2016)

Manitoba’s public agency for preventing workplace injury and illness is warning workers of the risks of extreme heat, both outdoors and indoors without air conditioning. Safe Work Manitoba (SWM) issued a statement on July 20, 2016, suggesting measures to keep workers safe and comfortable.

Employees in hot environments should wear lightweight, loose-fitting clothes, take breaks, drink cool liquids, and save physically demanding tasks for cooler times of the day. Fans should also be used indoors if there is no air conditioning. Symptoms of heat stress can include illnesses like headaches, dizziness, nausea, and exhaustion.

Workers should monitor themselves and co-workers for symptoms of heat stress, work in the shade whenever possible, and get used to high temperatures. If a worker is suffering from heat stress, colleagues should move the person to a cooler area, loosen heavy clothing, offer cool water, and call 9-1-1.

“Employers should work with their safety and health committees, worker representatives or workers to create a hot-weather plan, and determine work procedures for periods of elevated temperatures,” SWM states.

My opinion

The human body functions efficiently only within a very narrow range of internal temperatures. Normal deep body temperature is 37.6 degrees Celsius (99.6 degrees Fahrenheit) The temperature at the mouth is a little lower, about 37 degrees Celsius (98.6 degrees Fahrenheit) If the body temp. falls below 36.4 degrees Celsius or goes above 39.2 degrees Celsius the body functions are significantly impaired.

Often the heat source in a workplace is part of the work process, as in a steel mill or a laundry. In the summer, the outdoor temperatures can reach 35 degrees Celsius creating a possible hazard for some people working outside. If the body’s cooling system is overloaded, the body is placed under heat stress.

Effects includes heat cramps, heat exhaustion and heat stroke.

Heat Cramps are caused by a loss of fluids and body salts. Can be very painful and affect several different muscle groups (football players)

Heat Exhaustion results from the depletion of body fluids and salts. Symptoms include dizziness, nausea, and profuse sweating.

Heat Stroke is the failure of the body’s temperature regulating system, leading to a rise in body temperature that can cause death.

Assessing Heat Exposure – The hazard from heat stress is also increased by radiant heat. The Wet Bulb Globe Temperature Index (WBGT) is a commonly used indicator for measuring the conditions that may cause heat stress.

Controlling Heat Exposure – Heat exposure can be controlled at the source by redesigning equipment and work processes. Examples include insulating and isolating heat sources. Controls along the path include air conditioning as well as reflective barriers to reduce radiant heat. Several types of control at the worker can be found. Possible to schedule work/rest cycles and worker rotation, Climate-controlled booths, special equipment such as body-cooling vests and insulated or reflective clothing, and provisions should also be made for drinking water.

HRS Group Inc. has a great team that can help you with all your health and safety needs including Heat Stress. Contact Deborah toll free at 1-877-907-7744 or locally at 705-749-1259.

We can also be reached at

Ensure your workplace is a safe place.

Remember – In Canada, “All accidents are Preventable”

‘Work’ and ‘Play’ safe.

Daniel L. Beal

CHSEP – Advanced Level

CEO and Training Director

HRS Group Inc.





1 thought on “Blog Post #1401 – Heat-Stress Warning Released in Manitoba”

Leave a Comment