Fairbanks and the interior sometimes gets into the 90's. I think the record is 95 F. In Southcentral Alaska, where Anchorage is located, the mid 80's is about as warm as it gets. After living here for many years, a 70 degree day feels warm, and 80 F feels like a scorcher.

Regarding heatstroke, it does happen up here, though not commonly. I believe there have been cases amoung wild land fire crews on the fire line, and situations like that.

Regarding your general neck of the woods, Arizona people must be smarter than Californians. In the last couple of years I've visited Death Valley NP, and Joshua Tree NP. My visits were in the winter and the weather was quite nice for hiking. However, from all the warnings about, I got the impression that those parks have real issues with tourists getting cooked in the summer.