To stay hydrated! One of our regulars just passed out. Had to call him an ambulance. He works construction, then comes to sit on our patio to have a beer after work . Stay hydrated and take breaks in the shade/ac as often as possible. Probably preaching to the choir here, but maybe someone will need the remainder.

Still good tip. Also, even if riding around in a vehicle always bring along some water in case that radiator hose blows or engine stalls and you wind up sitting on the side of road. Warm water from the trunk is still better than none, under a hot 90* sun with humidity on top of the temp while waiting for a tow truck.

Step out of vehicle when safely to do so, and step to side of road (if able to do so safely and especially if shade trees nearby) in case someone isn't watching what they're doing and winds up colliding with your pulled over vehicle. While it may be hot, it will still be cooler than sitting in your vehicle with all that steel and glass collecting the heat and less air circulating within the vehicle.