Be sure you hydrate, summer heat can kill!
CDC suggest 1 cup min every 20 minutes.
If you are directly in the heat and working, 1 ounce per body weight lb consumed through out waking hours. So a 250lb man would need 250 ounces of water if he was in direct heat, consumed from wake up till bed.
A great way to know if you are hydrated, if you do not have to urinate every 2 hours, you are not drinking enough in the heat.