A common topic of conversation is wearing PPE when it is hot outside (or inside) Especially when heavier PPE and hoods are involved.
The question is:
How hot does it (normally) get at your location? (Actual temperature not the heat index)
80F/27C
90F/32C
100F/38C
110F/43C
120F/49C
Greater than 120F/49C - Frying eggs

118F a couple of times this summer. Our record (Phoenix, Arizona) is 122F

This one is difficult as I live and work in the foothills of the Northern Colorado Rockies and weather can be fickle. This summer has been cooler, with temps seldom over 100F (37.7C) and average humidity is up. In my 35 years here, we typically have a week or two with highs over 100F. This is enough that I have had to advise companies (and electricians) I work with about OSHA rules for heat stress, especially for outdoor work https://www.osha.gov/heat-exposure.

And we are now entering a cooler time of year. Interestingly, with temps down and humidity up this year, forest fires in my Colorado have also been down; even though we are still officially in a 23-year drought.

~doug

Because our mill is in a Northern location (-49F (-45C) lowest temperature last winter) the entire mill is inside a protective building including the furnaces. Heat can't escape easily, so some upper parts of the mill are above 130F (55C) in summer when ambient outdoor is 95F (35C) MCC rooms are generally air conditioned in summer but when that isn't working they can easily reach 113F (45C) in summer.

Interesting topic. Back before we had supplied air for our hoods, we set up an experiment to measure the amount of oxygen the user had while suited up. The results were not good and the levels would often dip below 19.5% under extended wear.

Mike

It should be noted that the normal sea level concentration of oxygen (O2) is 20.9%; where I live at 5,000 ft elevation it is normally 17.3%. Of course, acclimatization over several days is very important at high altitude (https://hypoxico.com/pages/altitude-to-oxygen-chart).

-Doug