The "dry heat" factor is real; I've lived back east as well, and you can keep it, lol. After 13 years I never managed to grow gills and got sick of trying.
BUT - while the ambient shade temp is tolerable well into the 100's (low 40's C) with <20% humidity (sometimes 5 or 7%), there are other factors to consider.
Firstly - a game we call "spot the locals". It's played by sitting somewhere where you can see a large group of people outdoors on a good hot day, especially if you can find an elevated position, and waiting for a breeze to pick up. The ones who immediately duck for cover are locals, lol. The ones that turn into the wind expecting a little relief and wince horribly at the blast furnace effect that follows - those are tourists, or really new to town, LMAO. So - no humidity = breezes SUCK, no relief there!
Secondly - whe I grew up back east and went to the beach, we had to watch the UV index and apply sunscreen or sunblock accordingly. It was a scale that I THOUGHT went from 1-10, and if yu wanted to tan you used SPF 8 through 12, and if the index was an 8 or heavan forbid a 10, you used SPF 30 or CRAXY strong stuff like SPF 45.
I didn't know the index went over 10 until it hit 12 one day in MARCH my first year here. We hit 14 or 15 in July. SPF 30 to 50 - sure, if you're only going to be out for a short while and you have a nice tan already. SPF 80 to 100 is a REALLY good idea if you're going to be out very long at all, and reapply it FREQUENTLY. I didn't even know they made it that strong till I got here,lol. And the 8 or 12 or 15 stuff? Yeah - not on the shelves. Anywhere. Might as well rub olive oil on your skin. Unprotected, I have managed 2nd degree sunburn in under 20 minutes of direct exposure to the sun.
So - keep to the shade, avoid the wind at all costs, and you'll be fine. Oh - when it breaks 110, the low humidity doesn't help much. 114 degrees F is just damn hot any way you cut it, lol. Though I once in Havasu once when the outside temps broke 130...