Using the Heat Chart

First you need to determine what the (a) temperature is and (b) what the percentage humidity it is.  Ideally it should be it an in vehicle, building or on person monitor (thermometers that also measure humidity can be purchased at any consumer goods store), use what is convenient for you. If you spend at least half your time in a vehicle for your duties, you are going to want get a reading of the temperature inside the driver's compartment.

Now that you know what the two values are, you need to check the two axis of the chart and see what heat stress value they intersect at. You then take that value and check on the course of action chart near the top left. Depending on where the value falls will give you a guideline on hydration, taking cooling breaks and the length of time and frequency they should be taken, etc.

This chart is just a guide.

You should pay close attention to how you feel throughout your day. Are you thirsty, light-headed, feeling tired? Even if the chart tells you that risk is low, you should listen to what your body is telling you!

An example of how to read and interpret the chart as follows:

The present temperature outside on your walk is 28°C. The humidity level is 50%.

 The action for a value of 33, when looked up on the small table in the top left part of the heat chart is to be alert for symptoms of heat stroke and to drink extra water.

·        38-39, it is recommended that a cup of water every 20 minutes be taken, as well as a 15 minute cooling break for every hour worked.

·        40-41, again the cup of water (240ml) every 20 minutes and a 30 minute cooling break for every hour of work.

·        42-44, cup of water every 20 minutes and a 45 minute cooling break for every hour worked!

·       Beyond this, it is only recommended that work be done on a medically supervised basis (which ain’t gonna happen).

Cooling breaks should be done in air-conditioned buildings, shaded areas where temperature severity may be lessened, and vehicles with air conditioning as a last resort.

You will have to be your own judge as to how well you are faring in the heat and humidity as everyone is affected differently in these conditions. Never be afraid to use your Right to Refuse unsafe work AT ANY POINT! It is your health and well-being, and only you are the best judge of how you feel.

If you have any worries or questions about what you are dealing with, do not hesitate to contact the office. We will all be dealing with this heat all summer long, and it is up to each and every one of us to do it thoughtfully and with resolve.

The corporation wants you to be safe and healthy. Make it more than just words.