. | If you have never heard of the humidex or not sure what it is, you are probably not alone. If you think it's something that has to do with the weather, you're right. The humidex is a shorter term used to express the 'humidity index'. It's a Canadian innovation first introduced in 1965. The humidex gives a better sense of just how hot is really is or how unconfortable it might be. For example, the temperature might be 32°C (or almost 90°F) and the humidex is 40. In other words, because of the ambient humidity, the 32 feels like a dry 40 degrees celsius (104°F). |
The index is based on a calculation of heat and humidity by using current air temperature and the dew point (the temperature and barometric pressure at which water vapour condenses into liquid). This is an important consideration, particularly for those of us with an excessive sweating condition. The skin has a significantly more difficult time ridding itself of sweat under moist or humid conditions. And so, when it's humid your skin will more likely remain wet, hence the discomfort. Given that the evaporation of sweat from our skin helps to cool off our body, it is particularly worrisome when humidity inhibits this process. As such, the core temperature of our body can remain high. |
When the humidex reaches 40 to 45, Environment Canada recommends avoiding exertion. Above 45 is considered dangerous and predisposes individuals to the risk of heatstroke. The winter time equvalent to the humidex is 'wind chill'. Ironically, this measurement was invented in the US, where winters tend to be milder than those above the 49th parallel. The Sweating Matters blog takes a break for the month of August but resumes in September. Thanks for your continued support and we welcome any comments. |