As they say about Phoenix, "it's a dry heat". It's near 20% humidity during peak sunlight during the day. I've been there in really hot summer weather and I was surprised by how really high temperatures didn't feel as hot as I was expecting. To give you an idea of how much this matters, in a gentle breeze, 39.5 C at 20% humidity feels like 57.3 C at 90% humidity.
People definitely don't faint within minutes in a typical Phoenix sunlight. The biggest risks are sunburn and dehydration, both of which take a lot longer.
The prior claim was that, in a gentle breeze, 135F and 90% RH was the same as 103F and 20% RH (that hotter AND more humid was the same as less hot and drier).
People definitely don't faint within minutes in a typical Phoenix sunlight. The biggest risks are sunburn and dehydration, both of which take a lot longer.