[synetic]

I think the writer means that the sweat evaporates so rapidly that it does not feel like you are sweating. That is, you don’t get drenched in sweat. I think during heat exhaustion the body stops sweating. Perhaps it’s easier to miss the signs of impending heat exhaustion in such conditions.

[pengaru]

It's really not, your mouth and throat become parched at that point, it's a very clear indicator you need to hydrate.

[synetic]

Needing to hydrate isn’t an indicator of impending heat exhaustion. I mean, people need to hydrate sometimes in cool weather. The Mayo Clinic doesn’t list needing to hydrate as one of the symptoms to be on the lookout for.

I’m not a doctor. I’m just surmising that if you aren’t drenched in sweat because it has evaporated so fast that one might not be aware of impending heat exhaustion. Obviously I might be wrong. Heavy sweating is a possible symptom of heat exhaustion.

https://www.mayoclinic.org/diseases-conditions/heat-exhausti...

Edit: At the end it does list dehydration as something to look out for. I have no idea what it is like in 110 degree weather with virtually no humidity. I’d guess even being well hydrated still makes it easy to get heat exhaustion.