Beat summer heat with quick cabin-cooling tricks, smart battery care and simple radiator maintenance to keep your car — and yourself — running smoothly all season.
What Does Summer Heat Do to Your Car?
| System | Effect of Heat | Quick Fix |
|---|---|---|
| Cabin | Trapped hot air makes the interior uncomfortable and hard to cool quickly. | Vent hot air out, then switch A/C to recirculate. |
| Engine & Cooling System | Low coolant, a stuck thermostat or a failing radiator can cause overheating. | Flush the cooling system regularly and check hoses and belts. |
| 12-Volt Battery | Heat evaporates internal fluids, weakening the battery over time. | Keep it fully charged with clean connections; test it each season. |
| EV & Hybrid Batteries | Range and efficiency drop as temperatures climb toward 95 degrees. | Precondition the cabin while plugged in and charge strategically. |
Quickly Cooling the Car
Efficiently cooling the car’s interior can reduce some strain on the vehicle and keep the driver more comfortable.
When you first get in, open the doors and windows to let the hot air out, and then, put the air conditioner on ventilation mode to help expel more hot air. Once the car starts to feel cooler, turn the air conditioner to recirculation and put it on its highest setting.
Starting the car and letting the air conditioning run while it’s parked is not the quickest or most economical choice, although it would do the trick in a pinch. Many newer models also come with an option to prestart and cool the interior from a key or mobile app.
More Ways to Keep Your Car Cool
- Embrace the shade. “Park in the shade or in a garage if you have one, and staying out of direct sunlight may help,” said AAA’s Car Doctor John Paul.
- Let in some air. Leave your windows open a crack, but only enough to let in a small breeze — and keep out rain and thieves.
- Invest in a windshield sunshade, especially if you can’t avoid the direct sun.
AAA members get discounts at NAPA Auto Parts, online and in select stores.
Why Do Car Engines Overheat?
When a car engine overheats, there is usually something wrong with the car’s cooling system. The car could be low on coolant, which reduces the temperature of the engine as it circulates. Another common cause is a malfunctioning thermostat. It could fail to open preventing coolant from reaching the engine. Another expensive cause could be a failed radiator, which cools off the coolant and blows hot air out of the car.
Make sure the cooling system is ready by having it flushed on a regular basis by a trusted auto repair facility. Coolant, also known as antifreeze, has anti-corrosion chemicals to prevent rust buildup inside the engine. Getting rid of old coolant, flushing the engine with fresh water and filling it with the proper mixture of the coolant formula and water, along with checking hoses and belts, will help a vehicle stand the test of hot summer driving.
What To Do If Your Car Overheats
If your car is starting to overheat, it may seem a bit sluggish. If the temperature gauge shoots up or if you see steam rising from the hood, pull off the road as soon as you safely can.
If you are unable to pull off immediately, turn off the air conditioner and turn on the heat. Yes, heat. This will help the engine cool a bit before you can stop.
Once stopped, turn off the engine and call for roadside assistance. Do not touch the hood.
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Car Maintenance for All Seasons
Car Battery Overheating
Consumer Reports has found that heat can weaken your car battery more than freezing temperatures.
Heat does not cause sudden battery failure but weakens a car battery over time. The optimum operating temperature for car batteries is 80 degrees, according to NAPA Auto Parts. But as soon as the car is moving, the temperature under the hood starts to rise.
If the temperature is hot enough, chemicals within the battery that conduct electrical charges begin to evaporate. That vapor can lead to battery corrosion over time, and ultimately, failure. AAA replaces over 2 million car batteries per year, and many car battery service calls happen in the summer.
“Here in the Northeast, batteries last about five years,” said Paul. “But in hot weather states, like Florida, Arizona and Texas, batteries only last about three years due to the heat.”
Ensuring the battery is fully charged and the connections are clean helps to maintain it. Periodically checking the charging and starting systems are a good idea as well.
If your battery does give out, call a AAA battery service professional who will come to you and test, clean or replace your battery. They also will properly recycle your old battery.
EV Batteries in Hot Weather
Summer heat takes a toll on electric vehicles, too. A new AAA study found that EVs lose about 10% of their efficiency and roughly 8.5% of their driving range when temperatures reach 95 degrees, compared with performance on a 75-degree day. For a driver, that means an EV rated for 250 miles of range might only deliver just under 230 miles on a scorching day. Hybrids aren’t immune either — AAA’s research showed a 12% drop in fuel efficiency for hybrid vehicles under the same extreme heat conditions.
To offset the heat-related range loss, AAA recommends checking tire pressure, removing roof racks and excess cargo weight, avoiding high speeds, preconditioning the cabin while still plugged in, using eco mode, parking in the shade and charging strategically — favoring Level 1 or Level 2 charging over frequent DC fast charging to help preserve long-term battery health.
Frequently Asked Questions
Does heat drain a car battery?
Yes, but not instantly. Heat speeds up the evaporation of fluids inside the battery, which weakens it gradually rather than causing sudden failure. Over time, that weakening leads to corrosion and, eventually, a battery that won’t hold a charge.
How can you protect a car battery from heat?
Keep the battery fully charged, make sure the connections stay clean, and have the charging and starting systems checked periodically. Parking in the shade also helps, since it keeps under-the-hood temperatures from climbing as high.
Do electric cars lose range in the heat?
Yes. A AAA study found EVs lose about 8.5% of their driving range and 10% of their efficiency at 95 degrees compared with 75 degrees. Hybrids take a hit, too, with a 12% drop in fuel efficiency in the same conditions.
How long do car batteries typically last in hot climates?
In hot-weather states like Florida, Arizona and Texas, batteries typically last about three years due to the heat. In cooler regions like the Northeast, batteries tend to last around five years.
What should you do if your car overheats while driving?
Pull off the road as soon as it’s safe. If stopping isn’t possible right away, turn off the air conditioner and turn on the heat — it pulls warmth away from the engine. Once stopped, turn off the engine, avoid touching the hood and call for AAA Roadside Assistance.
How often should coolant be flushed to prevent overheating?
Have the cooling system flushed on a regular basis by a trusted auto repair facility. Regular flushes remove old coolant, clear out rust-causing buildup, and refill the system with the proper coolant-to-water mixture.
Can extreme heat damage a car’s tires?
Hot pavement and high air temperatures increase tire pressure and accelerate wear, raising the risk of a blowout. Checking tire pressure regularly during summer months helps catch problems before they become dangerous.
What are your tips for cooling your car down as quickly as possible on a hot summer day? Share them in the comments below.
Last updated on September 22, 2026 by AAA Staff
Ellen is a content producer for AAA Northeast, covering automotive, finance, public affairs and electric vehicle news. She is a former newspaper reporter with experience writing for print and online publications about everything from higher education to sustainability. She recently returned to her native Long Island after living in Connecticut for 20-plus years, and has never met a beach she didn’t like.
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Pro-tip for keeping your car cool in the summer
Open your sunroof with the Tilt function to vent the rear edge. Since hot air naturally rises, the heat trapped inside the cabin will continuously escape through the top vent. This simple trick keeps airflow moving and ensures your car stays around ambient outside temperature rather than turning into an oven! Tip taken from termites that keep there nests cool with upward facing vents
If you have a sun roof, you can also leave it popped up when you park, so all the hot air comes out, and leave it open for a.few minutes as you drive away.