Plan for the wait
A parked car in the sun heats up fast, and asphalt and concrete give off heat too. If the engine and air conditioner still run, you can wait inside with the A/C on, as long as the car is in a safe place and the engine isn't overheating. If the engine is dead, the inside will warm up quickly.
Before you do anything else, tell whoever you call that it's hot and who's with you, especially children, older adults or anyone with a health condition. Keep water where you can reach it, not in a trunk that has turned into an oven.
Where to wait
Shade is the goal, but not at any cost. On a freeway shoulder, the safest place is often still inside the car, with the hazard lights on and your seat belt fastened. Crack the windows if the A/C is off. If it's getting dangerously hot inside and there's a wide shoulder with a patch of shade well away from traffic, behind a barrier for example, that's the better place to wait.
In a parking lot, move into a building or a patch of shade. Walk only if the path is short and safe. Don't walk along a live freeway to look for shade or a gas station. And never leave a child or a pet in a parked car, not even briefly.
Signs of heat trouble
Heat exhaustion can come on quickly. Watch yourself and anyone with you for heavy sweating, pale and clammy skin, dizziness, headache, nausea, cramps or unusual tiredness. Move to a cooler place if you can, loosen tight clothing, and sip water.
Heat stroke is an emergency. A very high body temperature, hot skin, confusion, passing out or a seizure means call 911 right away, even before the breakdown is dealt with.
If the engine overheated
If the temperature gauge climbs or steam comes from under the hood, pull over when you can, turn the engine off and wait. Don't open the radiator cap or the coolant reservoir while it's hot, because the pressure can spray scalding coolant. Waiting for it to cool takes a while in a Texas afternoon, so plan on that.
An overheated engine often means a leak or a failed part. TRA doesn't do mechanical repair or towing, so this is one for a tow company.
Heat and the usual suspects
Heat is hard on batteries and on tires that are already low, and summer is when both fail. A dead battery gets a jump start, which is $49–$75, and a flat tire gets a spare change, which is from $75, each plus a $19 dispatch fee charged once per job. We're open around the clock, and our average arrival is 30 minutes, with the actual time depending on location and traffic.
Common questions
In the open, if the engine isn't overheating and you aren't in a closed space, yes. Don't do it in an enclosed garage, and watch the temperature gauge.
More than you'd think. Keep several bottles in the car in summer. Sip regularly and don't wait until you're thirsty.
Stay with the car unless there's a safe, short route to shade or a business, and never walk along a live freeway. Tell dispatch if you move.