For spells there is lots of traditional guidance.

Be an early riser, like 4 AM. Do the heavy labor before it heats up. Take an extended break during the heat of the day - generally around 3 PM or so There are good reasons for siestas - it has nothing to do with laziness.

Keep hydrated and watch others for signs of dehydration. Drink water, not booze. Watch your electrolyte balance.

Seek shade and let any breeze circulate. Take advantage of any awnings, etc. and consider temporary fixtures.

Watch the relative humidity. it is much easier to be comfortable when RH is low. Then dousing clothing and surroundings with water is extremely effective. If RH is high, e really cautious because sweating does not cool you.

A broad rimmed hat is really vital if you are in the sun.

I remember a project in the Grand Canyon near phantom Ranch. We were on the job at 4AM, knocked off at noon, working on notes, etc. until after dinner, and then returned for about two hours. Temps regularly exceeded 100F. All survived....