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Beating the Heat

By Jada Solutions
Published: July 9, 2015 | Last updated: August 27, 2020 10:48:36
Key Takeaways

Extreme temperature safety.

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This article was originally posted by Taylor Hovan on

During the summer months, temperatures can reach well above comfortable working levels. While most of us enjoy a warm summers day, working in it can cause a lot of stress to our bodies. It is important to keep in mind that high temperatures can cause health risks, and to prevent these risks from occurring, precautionary measures should be used to keep workers healthy, hydrated, and happy.

Health Risks Associated With Heat

  • Heat edema: swelling due to heat
  • Heat rashes: tiny red spots on the skin, causes a prickling sensation
  • Heat cramps: sharp pain in the muscle, can occur indiviually or combined with other stress disorders. Caused by salt imbalance from failure to replace salt lost from sweat
  • Heat exhaustion: from excessive water and salt loss. Symptoms of heavy sweating, weakness, dizziness, nausea, headache, diarrhea, muscle cramps
  • Heat syncope: heat induced giddiness and fainting, caused by temporarily insufficient flow of blood to the brain
  • Heat stress: symtoms may include, sweating, headache, dizziness and fatigue, dehydration, muscle cramps and changes to breathing and pluse rate
  • Heat stroke: most serious heat illness, body tempature often great than 41 degrees celsius, partial loss of consciousness
  • Mental changes: increased irritation, mood changes, depression, aggression, and anger

Factors That Affect How Hot or Cold You Feel

  • Air temperature: measured with a thermometer
  • Other heat sources (radiant heat): examples such as direct sunlight, open flames, and machinery the generates heat
  • Relative humidity: the amount of moisture that is in the air, when the air has a higher humidity your sweat doesn’t evaporate in the air so you feel hotter, and a higher air humidity makes you feel colder because it increases conduction loss
  • Moving air: cools you down
  • Physical excertion
  • Clothing
  • General health
  • Age

Exposure Limits When Working Outside in Hot Conditions (Alberta)

  • These limits are to protect workers from heat related illnesses
  • For workers who work 8 hour shifts during a 5 day week should follow the ACGIH recommended threshold limit values for working in hot conditions
  • The TLV’s assume that the workers are hydrated, wearing lightweight clothing, and are in general health
  • Within each province there are different regulations on thermal conditions in the workplace

table - distribution of work in a work-rest cycle

Thermal Comfort at the Office

  • Thermal comfort means not feeling too hot or too cold when wearing normal clothing inside of the office
  • The air temperature, humidity, air movement should all be in the “comfort zone”
  • When the office is too hot workers become tired, and when it is too cold they become restless and easily distracted. These things are not good for productivity so to keep office workers awake and comfortable thermal comfort should be maintained at the office
  • Optimal temperatures for the office should be held at a constant range between 21-23 degrees celsius
  • The humidity level in the office should be above 20% and below 70%, around 50% is optimal, and the air velocity should be kept to a minimum to prevent distractions

Keeping Safe

  • The human body takes some time to adapt to any major temperature changes. The acclimatization period usually takes around 4-7 days. The best thing to do for your body is to gradually spend more time outside each day to let your body adjust safely to the heat. Remember though, everyone is different and people can acclimatize at different rates depending on their body
  • Stay hydrated when working outside, drink lots of water and other fluids to keep replenishing the salt and water your body looses
  • Wear a hat when working outside and sunscreen to protect yourself from the sun
  • Take breaks in shaded areas when possible, and don’t overexcert yourself with rigerous activities
  • Be aware of your bodies reaction signs to the heat

What Employers Can Do to Protect Their Workers in the Heat

  • Allow workers time to acclimatize to the high temperatures and monitor them to ensure that they are adapting
  • Provide water stations and ensure that all workers are keeping hydrated
  • Reduce physical activity, or change location of work to a more shaded area
  • Have a cooling station, and area with shade so workers can take breaks and cool down
  • Arrange for more physically demanding jobs to be done during the cooler parts of the day
  • Ensure clothing workers are wearing are appropriate for the jobs and weather conditions so workers do not overheat
  • Ensure that workers are following the ACGIH recommended threshold limit value for working in hot temperatures
  • Ensure that office workers have thermal comfort within the office

Keeping the Heat

The same risks caused by high temperatures that put stress on the body can also be applied during very low tempertures. Keeping safe and warm during the winter months is also important to keep workers productive and healthy.


Health Risks Associated With the Cold

  • Frostnip: mildest form of a freezing cold injury, when the top layers of skin freeze. Affected areas turn white and can feel numb
  • Frostbite: caused by exposure to extreme cold or cold objects, it is when the tissue temperature falls below freezing, or when blood flow is obstructed under cold conditions
  • Hypothermia: when the body is unable to compensate for its heat loss and the bodies core temperature begins to fall
  • Chilblains: mild cold injury from prolonged and repeated exposure for several hours to temperatures from freezing point up to sixteen degrees celsius. Affected areas will be red, have swelling, tingling and pain
  • Immersion foot: when indiviudals feet have been wet, but not freezing cold, for days or weeks. The main injury is to the nerve and muscle tissue. Symptoms can be tingling and numbness, as well as itching, pain, swelling of the legs, feet, or hands
  • Trenchfoot: the wet cold disease, from prolonged exposure in a damp wet environment from freezing point to about ten degrees celsius
  • Mental changes: loss of alertness, slurred speech, fatigue, lethargy or apathy

Keeping Safe

  • Keeping active can help increase the bodies core temperature
  • Make sure you are wearing protective clothing and footwear that is appropriate to the weather conditions. Make sure to layer up, because this is going to provide much better protection against the cold and gives you more control over changing temperatures
  • Have a work rest schedule the is appropriate to the weather temperature
  • Take warm up breaks in heated shelters, these can be tents, cabins, or rest rooms
  • The work being preformed should avoid causing excessive sweating, or if this type of work is necessary clothing changes should be done periodically to keep dry
  • Use safe work practices, and proper equipment design

table - threshold limit values for work-warm-up schedule for four hour shift

Factors That Affect Heat Loss

  • Wind chill
  • Quality of clothing
  • Wet clothing or footwear
  • Body type
  • Metabolism
  • Exposure to the sun
  • Age and physical condition
  • Adaption

What Employers Can Do to Protect Their Workers From the Cold

  • Allow workers time to acclimitize to the weather conditions
  • Ensure workers are wearing appropriate protective clothing and footwear
  • Provide workers a sheltered , heated place to warm up during breaks
  • Ensure workers take adequate breaks according to the temperature


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Written by Jada Solutions

JADA Solutions (HSE) Inc. was established in September 2007, as a Health, Safety and Environmental consulting firm, offering specialized services in Hazardous Materials, Indoor Air Quality, Industrial Hygiene and Health & Safety Services to those in Western Canada.

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