Heat Stress

Kwantlen Polytechnic University (KPU) has established the heat stress guidelines to protect the health of the university students, faculty, and employees. The goal of this guideline is to minimize the detrimental effects of excessive heat on KPU employees who are required to work outdoors or within indoor environments with elevated temperatures.  

What is Heat Stress?

“Heat stress” is the net heat load on the body from a combination of factors: environmental conditions, demands of the work, clothing, and personal characteristics. Four environmental factors affect the amount of stress a worker experiences in a hot environment: temperature, humidity, air velocity and radiant heat. Examples of radiant heat include direct heat from the sun or heat radiating from a source such as a furnace. Job-related factors that affect heat stress include work rate and physical effort required, type of clothing and protective equipment used, and duration of activity. All of these factors need to be evaluated in order to minimize their impact on the worker. Personal characteristics such as age, weight, physical fitness, and acclimatization to the heat also need to be factored in to determine those people and areas at high risk.

What Causes Heat Stress?

Working in hot environments, outdoors and indoors, can affect the body’s cooling system. If the body is unable to cool itself, heat stress can occur. If not recognized early, this can quickly develop into more serious and life-threatening conditions. Physical exertion and outdoor activities increase this risk if precautions are not taken.

What are the Signs and Symptoms?

As a worker’s body heats up it loses fluids and salt through sweat. As workers dehydrate, they are less able to cool themselves down. Workers in a hot environment should be aware of these warning signs of heat stress:

How to Prevent Exposures?

General Guidance

  • Monitor heat conditions and require workers not to work alone.
  • Communicate and review procedures with workers routinely.
  • Ensure there is adequate first-aid coverage and emergency procedures are in place.
  • Be aware of and check the signs and symptoms for yourself and co-workers. 

Review the Hierarchy of Controls

  • Move tasks to cooler days, times (typically before 11 a.m.) or environments.
  • Change work practices and policies to limit the risk.
  • Make physical modifications to facilities, equipment, processes to reduce exposure.
  • Establish cooling areas with shade and water.
  • Determine worker’s acclimation status.
  • Determine appropriate work-rest cycles; when a worker feels ill it may be too late.
  • Rotate work activities or use additional workers to reduce exposure.
  • Drink plenty of water.
  • Take rest breaks in a cool, well-ventilated area.
  • Wear light-colored, loose-fitting clothing made of breathable fabric, such as cotton. 

Common Outdoor Guidance

  • Protect yourself from the sun by staying in the shade, avoiding direct sun mid-day, wearing a hat and protective clothing, using sunscreen, and wearing UV-protective eyewear.
  • Seek cooler, breezier areas when outdoors, such as large spaces with lots of trees.
  • Stay hydrated by drinking water regularly, even more than you think you need.
  • Take it slow with outdoor activities, rest and relax often if you feel fatigued.

 Common Indoor Guidance

  • Make your space as comfortable as possible.
  • Close blinds and shutters during the daytime and open them at night if the space is occupied.  Open windows at night to let in cooler air if the space is occupied. Note: blinds, shutters and windows should always be closed if the space is not occupied to mitigate security risks
  • If you have air conditioning, use it to take the edge off indoor heat.
  • If you don’t have air-conditioning, take shelter in the coolest room in your home and use a fan. Blowing a fan across a pan of ice water can create a cool breeze.
  • Cool showers and misting yourself and your clothing with cool water will help keep you from overheating.
  • Stay hydrated by drinking water regularly, even more than you think you need.
  • Check in regularly with vulnerable people by phone or video.

What if Someone is Feeling ill from Heat Exposure?

Signs of progress to heatstroke should be considered a medical emergency where 911 must be called and first aid notified.
Typically for heat disorders other than Heat Stroke, the individual can be moved to a cooler environment and call first aid.

Additional Support, Resources, and References