With summer fast approaching, the temperature and humidity are sure to rise. These increases dramatically increase the risk of heat stress to all workers. Heat Stress occurs when the body absorbs more heat than it can get rid of, essentially, overheating of the body.
Heat stress can lead to very serious injury, or possibly even death. With injury or death a plausible outcome, it is extremely important for employers to provide preventive measures to minimize the likelihood of an employee being injured due to heat stress.
The most effective type of preventative controls an employer can implement is engineering controls. Engineering controls are controls which are designed to isolate the employees from the hazard. Examples of effective engineering controls used for heat stress are:
Reduce worker activity through automation or mechanization
Cover or insulate hot surfaces to reduce radiant heat
Shield workers from radiant heat
Provide air conditioning and/or proper ventilation
Provide fans for spot cooling
Using dehumidifiers for reducing humidity
Another set of controls that are effective when dealing with heat stress are administrative controls. Administrative controls are not designed to eliminate the hazard; they are used to shape the way in which employees work. The main goals of administrative controls are to prevent or limit exposure to hazards. There are several useful administrative controls to preventing or eliminating heat stress.
Acclimatization means to gradually expose the employees to the hot conditions. This may be done over several days or several weeks, depending on individual variables, such as age, weight, various health conditions, etc.
Other valuable administrative controls include:
Working in partners or groups
Appropriate work-rest cycles
Appropriate work schedule
Scheduled water breaks
Personal Protective Equipment (PPE)
The final method of control is personal protective equipment. PPE is essentially the last line of controls employees can use to protect themselves from heat stroke.
Effective PPE for heats stress may include:
Proper clothing such as,
- Light summer clothing
- Light colored clothing
- Long sleeve shirt and pants to protect from sun
- For very hot environments, consider air, water or ice-cooled insulated clothing
- Vapor-barrier clothing
Remember, always stay hydrated. Drinking plenty of fluids, such as water, sports drinks and juice, will replenish important vitamins and minerals lost over the duration of a shift. It is also important to stay clear of beverages such as alcohol, coffee, and other beverages containing caffeine, as these will dehydrate the worker. A simple way to help stay cool at the worksite is to have frozen wet face cloths that can be placed on the back on the neck to cool core body temperature.
Ontario Ministry of Labour. (2013). Heat Stress. Retrieved from
Worksafebc. (2007). Preventing Heat Stress at Work.