Though, TBF, the NPS, who admin that thermometer, admit it's in a very hot location next to the ranger station, and they keep it there for bragging rights.
I've worked in 120° heat and it's not fun. Especially when you go back in the truck and it's 140° and the "cooling fan" just turns the truck to a convection oven.
I don't think people take dry heat seriously. Humid heat is obviously dangerous because you can't sweat the heat out of your body as efficiently, but dry heat at these temperatures feels like walking outside and holding a hair dryer to your skin. It's so fucking hot. You can feel the sun touching your skin like its physically reaching out. You sunburn from 5–15 minutes in the sun without sunblock. And it doesn't cool off either, not really. Temperatures stay in the high 80s and low-to-mid 90s all night. "But it's a dry heat" is really dismissive of how dangerous an unwavering 90–120° is, in this case for weeks on end.
You're right, feels like stepping into an oven, as soon as you're in the sun you feel like you're starting to literally cook. It's awful, and in a city it doesn't cool much so you can't cool off. If heat doesn't get you the first day try the next when you're with down a little.
I'd like to see how a dry heat compares because I've always heard it was better. This past week where I'm at in the states has been terrible, triple digit heat (I think it was 102 on Wednesday) with super high humidity and ridiculous UV levels; the air is thick and like a blanket wrapped around your head the moment you walk outside. Nights have been upper 70's-low 80's, I know it could be worse (thank god for a pool and AC), but this is way hotter than when I grew up.
Thermometer from my deployment to Iraq in 2008. Pretty sure that day we were over 130F. I have to do some more digging but I believe I have a photo of one over 140F.
Anything metal becomes burn your skin hot in just a few minutes. Exposed skin is very uncomfortable almost immediately.