UP 844 Heading Toward Cheyenne

Probably not has hot as you may think. I recall coming back from one of those political conventions in Los Angeles, back in 2001, with Challenger 3985. The California and southern Utah desert was between 102 and 106, according to the wayside detectors, and our thermometer in the cab eventually got to 145 degrees. The glue holding the thermometer to the diesel MU Control Box finally gave up, and the poor thing fell off and hit the steel deck.

Engineer Bob Krieger and I still talk about those two days. We had to drink two bottles of water and a bottle of PowerAid, continuously, but upon arrival at the motel that evening, none of us could pee a drop! The humidity was below 10%, and actually we didn't feel all that uncomfortable, since we were not swimming in our own sweat.

That is the danger of low humidity.  You will sweat, but will not feel it because of the air's being so dry.  HW and the steam team were very wise in keeping their fluid intake up!

It is amazing just how much water you can take in on a very hot day.  Heavy exercise, or work you can easily talk gallons (about (4) liters). Easterners familiar with high humidity and dripping wet sweat need to know that the low humidity/high temp west is dangerous, in that you don't feel the discomfort that you are uses to.    

I am from New York. Last time I was in the High Desert with low humidity and three figure temps, I was en-route from the Grand Canyon to Phoenix and I was drinking a lot.  I had to. I felt like a sponge that was drying out and it hurt!