I was reminded of the possibility of heat stress  in our shops when I started the car the other day.
107 degrees copy
Early in my career in the blast furnace casthouse and on the ore docks staying safe from the effects of high heat was a daily event.
On top of the coke plant batteries it was a minute by minute struggle.
While we do not face these same levels of heat in our precision machining shops per se,  the summer can bring high, unaccustomed temperatures. Temps of over  100 degrees are easily attained in places with high solar gain and stagnant air.
Unloading trucks outside or doing external work on roofs or even landscaping can put even the most fit worker into some form of heat stress if precautions have not been taken.
Here is the OSHA pocket card for Heat Stress Awareness
Click here for link to the PDF
OSHA HEAT STRESS QUICKCARD ENGLISH V_3_8.30.11 :OSHA HEAT STRESS
OSHA HEAT STRESS QUICKCARD ENGLISH V_3_8.30.11 :OSHA HEAT STRESS