They evolved for rather hot and rather arid conditions.

Most of my cats spent most of their taime outside from the time it got
warm in the spring until well into the current heat wave.  They
decided that the air conditioning wasn't so bad after all about the
time the afternoon high temperatures got above about 95-97 degrees F.
for several days in a row.  They have water outside, and plenty of
shade and other shelter.

Dunno, but I adopted my cat when she was a few weeks old when she was
seeking shelter from the sun under a car parked beneath a carport on
asphalt.  The temperature was about 115 degrees or so.

After taking her inside and giving her a slice of turkey and some water,
 I took her to a vet and despite being undernourished, having an
upper-respiratory infection and being shot with a pellet gun, she was fine.

Yep - she was NOT dehydrated, which is what I would have suspected to be
the first problem.

She's a long-hair cat too, so in my un-educated merely anecdotal
opinion, while heat may be uncomfortable, I doubt it is a serious issue
for the health of cats.

Speaking for myself, as a human, I love 100 degree weather, as long as
it's not accompanied by humidity.