Heatstroke: more than just the temperature!

Heatstroke: more than just the temperature!


Heat can be unforgiving. The work is strenuous, the heat wave is at its peak and suddenly, the body cannot cool itself anymore. It struggles to maintain a body temperature around 37-degree Celsius, its usual and ideal temperature. If nothing is done and the body temperature exceeds 40 degrees, you will suffer from heatstroke. In some cases, it can even be fatal.

Some basic principles

Multiple factors may increase the risks. The good news is that in each case it is easy to correct the situation! Raise the awareness of your staff to ensure they adopt safe behaviours.

  • Remind them to always keep water close by
  • Recommend to avoid sun exposure or work where there is inadequate ventilation
  • Encourage them to take regular breaks
  • Mention the importance of wearing clothing that helps wicking sweat away

The “real” temperature

Are these principles strictly followed by your teams? That’s not all! Besides these precautions, ensure that their water consumption matches up the quantity required due to the temperature.

Just remember that 30-degree Celsius indicated on a thermometer is not the real temperature! Other factors must be taken into consideration:

  • Relative humidity

If the humidity exceeds 35%, it will increase the effect of the heat. A relative humidity of 60% is corresponding of an increase of 5 more degrees!

  • Sunshine

Direct exposure to sunrays is obviously more dangerous than working under cloudy overcast skies or indoors.

  • Clothing

Wearing coveralls increases the heat sensation. Clothing that does not breathe (for example, waterproof) can have a negative effect.

Drink regularly and in sufficient quantity!

Once the temperature is known, your employees must stay hydrated following a pre-established strategy, even if they are not thirsty!  

It is recommended to drink approximately 250 ml of water every 20 minutes if the adjusted temperature is about 39 degrees or less.

In intense heat, you must drink one glass every 15 minutes or even every 10 minutes!  

To learn more about how to protect your staff against the heat, ask SPI for advice!