Much depends upon acclimatization, whether it's temps (high or low) or altitude.
. . . much depends upon giving our bodies time to adapt.
Couldn't agree more Kevin. I grew up in Atlanta in the late 50s and 60s without an air-conditioned home or auto. I distinctly recall having the first window A/C unit in our home in 1970. I didn't drive a car with a functional A/C till I was in my early 20s. The thing is, despite Georgia's excessive, never-ending heat index in the summer, I don't recall being particularly uncomfortable. It really is relative to the individual's conditioning.
All that mining and native history in Death Valley didn't take place in air-conditioned comfort. Nowadays, though, stepping out of a cool car cabin into that DV heat can be a shock to the system. My personal high-temp experience in DV was 126 degrees last July, returning to Vegas from Whitney. I've driven this park a number of times over the years, but I had never before seen the portable, bright orange "Excessive Heat Warning" signs that the NPS placed all along 190 that day. When DVNP feels heat is "excessive", you pay attention!
