Why care about Wet Bulb Temperature? - CycleBlaze

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Why care about Wet Bulb Temperature?

Graham Smith

The short answer is that Wet Bulb Temperature  (WBT) can kill us cycle tourers if it is above 35°C. The WBT story as told by a satirical but scientifically accurate cartoonist known as “First Dog on the Moon”

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1 week ago
John PescatoreTo Graham Smith

In the US, the "Feels Like" temperature or Heat Index is more commonly quoted by the professional weather guessers - I think it is roughly equivalent to the wet bulb temperature. "Feels like"/Wind Chill is the winter equivalent.

I kinda feel like those numbers are mainly used by local TV "Storm Centers" (what used to be called weather teams) get more air time - in particular the Wind Chill, which seems mostly relevant if you regularly go naked outside in the winter...

But before those heat/humidity warnings were routine, years ago  during the week long Cycle Across Maryland tour on a century ride day MD's on eastern shore the last 40 miles after the lunch break were through air temps of 95F/35C with high humidity, no shade and heading southwest into the hot wind. Riders were dropping like flies or abandoning at rest stops.  These days that would be a start early/get done early/carry more water day - or only have the metric century ride. Climate change has meant we get 50% more days over 90F now compared to the long range historical average.

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6 days ago
Graham SmithTo John Pescatore

John I can’t ever recall cycling in extreme humid heat, which is why it surprised me to learn how deadly it can be. I’ve often cycled in high temperatures… 38°C, 39°C and even up to 42°C which eventually brought me to a halt. But these high temps (common in S.E. Australian summers) were in a relative humidity of 5% of lower. Evaporative cooling via sweat and a water soaked jersey worked well to unload heat when humidity was low. 

I doubt whether I’d last long cycling in your southern states summer humidity. I’d be bunkering down in an air conditioned building or dozing under a shady tree. 

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6 days ago