Live Chat
Skip to main content

Heat Stress

Heat stress

What is Heat Stress?

Heat stress is a condition that can take many forms, depending on the severity of external and internal factors and, of course, the condition of the individual.  The heating and cooling balance in the body depends on:

  • air temperature
  • humidity
  • radiant heat
  • physical activity
  • colling (by the evaporation of sweat)
  • body adjustments (acclimatization

Heat stress is an issue in many workplaces all year round.  Heat stress not only affects employees working outdoors, but also those who are exposed to radiant heat or who come in direct physical contact with hot equipment as part of their job.

What the law says

Employers have a duty under Section 25(2)(h) of the Occupational Health and Safety Act to take every precaution reasonable in the circumstances for the protection of the worker.  This includes developing policies and procedures to protect workers who have direct physical contact with hot equipment, are exposed to radiant heat sources, or are working in hot weather.

For compliance purposes, the Ministry of Labour recommends the current threshold limit value for heat stress and heat strain (published by the American Conference of Governmental Industrial Hygienists).  These values are based on preventing unacclimatized workers' core temperatures from rising above 38ºC.

How can heat stress affect your business?

A worker expending large amounts of physical energy in a hot and humid environment, without regular rest or water breaks may eventually experience heat exhaustion, fainting, heat stroke or heart attack.  Long-term, this can lead to reproductive problems, heart and lung strain and other complications, and may even result in death.  It is critical to address this hazard to protect employees and your business from lost productivity, reduce morale, as well as fines and penalties.

What you can do

There are many ways you, as an employer, can take measures to ensure that your staff is healthy and safe from heat stress, including:

  • Make staff aware of the hazard of heat stress and provide the necessary training on first aid reporting, emergency response, medical monitoring, etc
  • Design work to allow for adequate rest and hydration breaks
  • Conduct regular inspections to identify potential hazards and ensure that the necessary controls to prevent an incident are in place
  • Investigate heat stress incidents that occur in the workplace
  • Provide necessary protective equipment and clothing