Yeah I don't trust car thermometers either.
What state are you in?
Bout 8 or 9 years ago, in Rancho Cucamonga Ca, it was over 120 for a few days.
My restaurant had to shut down because the 6 AC units shut down from being too hot and the walk in freezer was thawing.
We shut down for a week, and none of the cigarette smokers could bear a smoke.
Here in riverside, last week it hit 115.