Driving safely in extreme heat comes down to preparation and smart precautions. Make sure your car’s cooling system, battery, tires, and other critical components are in top shape, carry an emergency kit (including plenty of water), and plan for breaks or cooler travel times. These steps significantly reduce the risk of overheating engines, tire blowouts, or heat-related emergencies on the road. Remember, heat can be tougher on car batteries than even freezing winter cold, and interior car temperatures can soar above 130 °F on a 90 °F day – so staying vigilant is key. (For questions or help, call Insure On The Spot at 773-202-5060.)
Why Is Extreme Heat Hard on Cars and Drivers?
Extreme heat can push cars and drivers past their limits. High temperatures can cause engines to overheat, fluids to evaporate faster, and rubber components (like belts, hoses, and wipers) to degrade more quickly. Tires are also at risk: for every 10°F increase in ambient temperature, tire pressure can rise by about 1–2 PSI, and underinflated tires in hot weather are prone to blowouts. Additionally, the blazing sun can make vehicle interiors dangerously hot for occupants, and can even impair driver visibility with glare.
For drivers, extreme heat can lead to fatigue or heat exhaustion, especially on long trips without proper hydration or air conditioning. And of course, never leave children or pets in a parked car during a heat wave – even a few minutes can lead to heatstroke, as a child’s body heats up 3–5 times faster than an adult’s.
How Can You Prepare Your Car for Extreme Heat?
Before venturing out on scorching days, take time to prep your vehicle. Proper maintenance is your first line of defense against heat-related breakdowns. Here are key areas to check:
Check Your Cooling System and Fluids
Your engine’s cooling system works overtime in summer. Inspect the coolant level and top it off if it’s low – coolant (antifreeze) is crucial to prevent overheating. Make sure the coolant mixture meets your manufacturer’s specs (typically a 50/50 mix of antifreeze and water). It’s also wise to have a mechanic pressure-test the system for leaks and flush old coolant if needed. Never remove the radiator cap when the engine is hot – boiling coolant can erupt under pressure and cause serious burns. In addition, check your oil level and other fluids (transmission, brake, power steering, etc.) regularly; low fluid levels can reduce cooling efficiency and increase the chance of overheating. Consider getting an oil change if it’s due, since fresh oil helps the engine run cooler.
Edge-Case: Can extreme heat cause your car to run out of fluids faster? Yes – high temperatures can accelerate fluid evaporation and degradation. Motor oil and transmission fluid can thin out in extreme heat, and water content in coolant may evaporate over time. That’s why it’s critical to check and top off all fluids frequently during summer. If you notice any fluid leaks, address them promptly before they lead to bigger problems.
Test Your Battery
Both extreme cold and extreme heat can reveal a weak car battery, but many drivers don’t realize heat can be even more brutal on batteries. High temperatures and vibration are a battery’s worst enemies, potentially causing fluid to evaporate and internal components to break down. If your battery is more than 3 years old or showing signs of weakness (slow starts, corroded terminals), have it tested by a technician. Clean any corrosive buildup on the terminals and ensure the cable clamps are tight. It’s much cheaper to replace an aging battery proactively than to get stranded with a dead one in sweltering heat. (As a bonus tip, make sure the battery is securely mounted to minimize vibration damage.)
Inspect Belts and Hoses
Heat can accelerate wear on rubber belts and hoses under your hood. A broken drive belt or a burst radiator hose can instantly disable your car – not something you want happening on a 100°F day. Before summer really heats up, inspect all belts for cracks, fraying, or glazing. Likewise, check hoses for any bulges, soft spots, cracks, or leaks, and ensure hose clamps are snug. If you’re not comfortable assessing these yourself, ask your mechanic to take a look. Replacing worn belts/hoses now is far better than dealing with a breakdown later.
Check Tire Pressure and Tread
Tires need extra attention in extreme heat. Underinflated tires flex more and build up excess heat on hot roads, greatly increasing the risk of a blowout. Check your tire pressure at least monthly (and before long trips) using the recommended PSI in your owner’s manual or driver’s door jamb. Remember to check them when the tires are “cold” (not right after driving) for an accurate reading. Inflate to the vehicle manufacturer’s recommended pressure, not the max PSI on the tire sidewall. Also inspect your tire tread; worn tires are more likely to fail in harsh conditions. If your spare tire is accessible, ensure it’s properly inflated and in good shape too. Hot weather or not, tire maintenance is critical year-round – but it’s especially vital when pavement temperatures soar (road surface temps can be much hotter than the air!).
Edge-Case: Why do tires blow out more often in hot weather? Heat causes air inside tires to expand, raising the pressure. If a tire is worn out or already underinflated (causing flexing), this extra stress can lead to a blowout. Also, summer road trips at highway speeds for long periods put added heat into the tires. To avoid this, always keep tires properly inflated and don’t overload your vehicle – an overloaded car + underinflated tires + 100°F weather is the perfect recipe for a tire failure.
Make Sure the A/C Works
A functional air conditioning system isn’t just a luxury in extreme heat – it’s important for driver alertness and safety. Before the hottest days hit, test your A/C to ensure it’s blowing cold. If it’s not as cool as it used to be, the refrigerant level might be low or there could be another issue; have it checked by a certified technician. Also, if your car has a cabin air filter, replace it as recommended (a clogged cabin filter can reduce A/C efficiency and airflow). A strong A/C will not only keep you comfortable but also help prevent heat-related fatigue while driving. If your vehicle lacks air conditioning or it fails, plan accordingly with ventilation (open windows, use windshield sunshades when parked, etc.) and frequent breaks to cool off.
Fuel Up and Plan Ahead
Don’t forget about your fuel. In extreme heat, it’s wise to keep your gas tank at least half to three-quarters full. This isn’t because gas will evaporate en masse (modern fuel systems are sealed), but rather in case you get stuck in traffic or detoured, you’ll have plenty of fuel to run the A/C or reach assistance. Running out of gas on a desolate highway in 110°F weather is not only inconvenient – it can be dangerous. Additionally, consider carrying extra coolant and a bottle of water in the trunk for emergencies (just be sure to secure them to prevent spills).
What Are Smart Driving Habits for Extreme Heat?
Even with a well-maintained car, how you drive in extreme heat can make a difference. Adjust your driving habits and plans to minimize stress on your vehicle (and yourself):
Avoid the Hottest Part of the Day (If You Can)
During a severe heatwave, try to schedule trips for early morning or late evening when temperatures are lower. Mid-day (roughly 10 AM–4 PM) is often the most blistering period. If you can avoid driving during those hours – or at least avoid stop-and-go city traffic then – do so. Your engine, tires, and A/C will have an easier time, and you’ll be more comfortable as well. (Plus, you might avoid the daily ozone/heat-related traffic jams common on super hot afternoons.)
Plan Routes and Take Breaks
For longer drives, plan regular rest stops – say, a 15-minute break every 2 hours. This gives you a chance to stretch, rehydrate, and let your car cool down a bit. If possible, route your trip to include shaded or air-conditioned stops. Whenever you park, try to find shade or use a windshield sunshade to keep the interior cooler. Some drivers even slightly crack their windows when safely parked to vent hot air (just be security-conscious). Also, consider taking highways instead of side streets if available. Major highways tend to be better maintained and less prone to sudden stops than local roads – which can help reduce strain on your car. Just be sure to watch your speed and keep an eye on your gauges regardless of route.
Watch the Road (and Your Temperature Gauge)
Extreme heat can sometimes cause pavement to buckle or make tarry road surfaces “bleed,” creating slick spots. Stay alert for road hazards like new cracks or potholes that could form in heat, and try to avoid them – a sharp jolt from a pothole on an overheated tire could spell trouble. Meanwhile, keep an eye on your car’s temperature gauge or warning light. If you notice the engine temperature creeping into the red zone or a dashboard warning light for overheating, take it seriously. Turn off the A/C, turn on the heater (more on that below), and find a safe spot to pull over as soon as possible. It’s better to pause a trip than to push a hot engine too far.
Don’t Overload Your Vehicle
Heavy loads make the engine and brakes work harder, and tires heat up more under extra weight. If you’re moving luggage or gear for a summer trip, try not to exceed your vehicle’s load capacity (check the manual for the gross vehicle weight rating). An overloaded car climbing a hill in 100°F heat with the A/C blasting is asking a lot from your cooling system and transmission. Pack smart and lighten the load where possible – your car will thank you.
How Can You Stay Cool and Safe Inside the Car?
Keeping yourself and your passengers safe is just as important as caring for your car. Extreme heat can quickly affect your health and mood while driving, so take steps to stay cool:
Stay Hydrated and Dress for the Weather
Bring plenty of water for everyone in the car. On long drives or in areas with very high temperatures, consider keeping a small cooler of water bottles within reach. Sip water regularly to prevent dehydration – even with A/C on, you can get dehydrated over hours on the road. Also, dress in lightweight, light-colored clothing that breathes. Natural fabrics like cotton can be cooler than synthetics. Don’t forget sunglasses to reduce glare and a hat if you’ll be in and out of the sun. If you start feeling overheated or dizzy while driving, that’s a sign to find a cool spot and take a break.
Use Sun Protection and Ventilation
Sunshine heating up your cabin? Use sun visors and invest in a quality windshield sunshade when parking to block direct sunlight. Window tinting (within legal limits) or cling sun shades for side windows can also cut down on solar heat buildup. When you first get into a car that’s been parked in the sun, roll down the windows for a minute or open the doors to flush out the hottest air before turning on the A/C. It can easily be 30-40°F hotter inside the car than outside, so giving that heat a quick escape makes your A/C’s job easier and cools the cabin faster. If your air conditioning is weak or non-existent, max airflow through open windows (or even a portable 12V fan) can help a bit while driving – but in truly extreme heat, plan routes that allow for cooling stops.
And never underestimate sunscreen on exposed skin, even inside the car. You can get a sunburn on a long drive if sunlight is streaming in. A sunscreen of SPF 30+ on your arms, face, and neck is a smart move for all-day trips in the sun.
Keep Children and Pets Safe
Young children, elderly passengers, and pets are especially vulnerable to heat. If you’re traveling with kids or animals, ensure the A/C reaches the back seat or adjust vents accordingly. For pets, bring a travel water bowl and stop for water breaks. If anyone appears red-faced, lethargic, or ill from the heat, get off the road and cool down.
Most importantly, do not leave children or pets unattended in a parked car – not even for “a minute.” In 90°F weather, the interior of a car in direct sun can exceed 130°F in just 10 minutes, creating life-threatening conditions. Cracking the windows does not prevent this rapid heat rise. Tragedies have occurred when caregivers “just ran into the store” and got delayed. If you see a child or pet alone in a hot car, call 911 immediately and attempt to get them out safely according to local laws. Heatstroke can be fatal in a very short time.
(Fun fact: Cars can heat up even on seemingly mild days. Even at an outside temperature of 60°F, sunlight can quickly make a car’s interior dangerously hot. Always err on the side of caution.)
What Should You Do If Your Car Overheats While Driving?
Despite all precautions, it’s possible for a car to overheat in extreme heat, especially during heavy use or climbing hills. Knowing how to respond immediately can save your engine (and possibly save you from an accident):
Watch for Warning Signs
Most cars have a dashboard temperature gauge or an indicator light. If you see the needle spiking into the hot zone or a red temperature light, or notice steam coming from under the hood, your car is overheating.
Turn Off the A/C and Turn On the Heater
This sounds counterintuitive, but shutting off the air conditioning reduces strain on the engine, and turning the heat on full blast can actually help draw excess heat away from the engine into the cabin. Yes, it will get uncomfortable, but it can buy you time to find a safe spot. Immediately roll down the windows if you do this, because the cabin will heat up.
Pull Over Safely and Shut Off the Engine
Do this as soon as you can find a safe area off the road. Continuing to drive with an overheating engine can cause severe, permanent engine damage (like a warped cylinder head or blown gasket). It’s better to stop and let things cool down.
Wait for the Engine to Cool
Pop the hood (carefully – use a glove or towel to avoid burns) to vent heat, but do not open the radiator or coolant reservoir cap while the engine is hot. The coolant is under pressure and can spray out. It typically takes at least 20–30 minutes for an overheated engine to cool. Do not pour cold water on the engine; just wait it out. Use this time to hydrate yourself and, if you have a cell signal, consider calling for roadside assistance.
Add Coolant/Water if Available
If you have extra coolant (antifreeze) and the engine has cooled down, you can top off the radiator or overflow reservoir very carefully. In an emergency with no coolant, adding plain water is better than nothing to get to a service location – but remember to get proper coolant added as soon as possible. Note: Many modern cars have a sealed cooling system; if you’re not sure what to do, it’s safest to wait for help.
Restart and Seek Help
After things have cooled and if the car seems driveable, you might attempt to carefully drive to a nearby mechanic while keeping an eye on the temperature gauge. Keep the heater on to assist cooling. However, if the engine heats up again or you’re in doubt, it’s best to call for a tow. Engine repairs are expensive; it’s not worth risking a total breakdown. Use your judgment – safety first.
Pro Tip: Always carry a phone charger in your vehicle. If you have roadside assistance coverage (for example, Insure On The Spot policies include 24/7 roadside assistance for emergencies), you can call for help to get towed or repaired. It beats being stranded in dangerous heat trying to fix a car by the road.
What Emergency Supplies Should You Carry for Summer Driving?
Even a well-maintained vehicle can run into trouble, so it’s wise to keep an emergency kit in your car, especially during summer travels. In extreme heat, a breakdown without the right supplies can quickly become hazardous. Prepare a kit that includes:
- Water – Plenty of drinking water for all passengers (at least a few bottles, more on long trips). In case of a breakdown, staying hydrated is your #1 priority.
- Non-perishable snacks – High-energy snacks (granola bars, nuts, dried fruit) can be a lifesaver if you’re stuck waiting for assistance. Avoid foods that will melt.
- First aid kit – Include band-aids, antiseptic wipes, pain relievers, and any personal medications. Heat-related breakdowns can sometimes involve minor scrapes or just headaches from stress.
- Sun protection – Sunscreen, a wide-brimmed hat, and sunglasses. If you must be outside the car waiting for help, you’ll want protection from the sun. A light long-sleeve shirt can prevent sunburn.
- Jumper cables – In case a heat-weakened battery dies, jumper cables (or a portable battery jump starter) will help you get moving again or assist a fellow motorist.
- Flashlight and extra batteries – Breakdowns can happen at night too. A flashlight helps with car repairs or signaling, and it’s useful if you wait till dusk to continue driving after a heat delay.
- Road flares or reflective triangles – To alert other drivers if you’re stopped on the roadside. Heat haze can distort visibility, so clear warning signals are important.
- Basic tools and duct tape – A small tool kit (screwdrivers, pliers, wrench) and duct tape can help with temporary fixes, like patching a hose leak, to limp to a service station.
- Extra coolant and oil – As space permits, carry a bottle of engine coolant and a quart of motor oil. If your engine runs low or overheats, these can get you back on the road (or at least prevent damage while help is on the way).
- Spare phone charger or battery pack – If your car’s electrical system fails or you’re low on car battery, a charged power bank can keep your phone alive to call for help and stay informed.
Stay Prepared and Stay Safe
Summer is a fantastic time for road trips, beach days, and outdoor adventures. Driving in extreme heat anywhere in the U.S. means you need to be a bit more vigilant, but it doesn’t have to spoil your plans. By taking care of your car’s needs and your own, you can confidently hit the road even when the thermostat spikes. Being prepared will pay off with many miles of trouble-free, fun driving this season. Stay safe, stay cool, and enjoy the ride!
(And remember, if you have any questions about safe driving or want to review your auto insurance before your next trip, Insure On The Spot is here to help. We offer affordable auto insurance with 24/7 roadside assistance included, so you can drive with peace of mind. Feel free to give us a call at 773-202-5060 – we’re happy to assist.)
FAQ: Driving in Extreme Heat
Q: How do you drive safely in extreme heat?
A: To drive safely in extreme heat, prepare your vehicle beforehand and practice good habits on the road. Make sure your cooling system, battery, tires, and fluids are all in good condition, and carry emergency supplies like water and coolant. While driving, use your air conditioning (if available), plan trips during cooler parts of the day, and keep an eye on your temperature gauge. If your engine starts to run hot, turn off the A/C, turn on the heater, and pull over to let the car cool down. Staying hydrated and taking breaks will also help you remain alert and safe.
Q: How can I prevent my car from overheating in hot weather?
A: The best way to prevent overheating is through maintenance and vigilance. Ensure your car has the proper amount of coolant and that the radiator and cooling fans are working correctly. Check that drive belts (which turn the water pump) are in good shape. When driving, avoid heavy stop-and-go traffic in peak heat if possible – idling in traffic puts a lot of stress on the cooling system. Use the car’s heater strategically if you notice the temperature gauge rising, as it can pull heat from the engine. Also, if you’re climbing a long hill on a very hot day, consider turning off the A/C temporarily to ease the burden on the engine.
Q: What should I do if my engine starts to overheat while driving?
A: If you see signs of overheating (temperature gauge in the red, warning light, or steam under the hood), act fast. Turn off the air conditioning and turn your heater on full blast – this helps draw heat away from the engine. Then safely pull over as soon as you can. Turn off the engine and open the hood to vent heat. Do not open the radiator cap until the engine has thoroughly cooled (usually at least 20-30 minutes). Once cooled, you can check coolant levels and add coolant/water if you have some. If the engine cools down, you might restart and drive carefully to a service center, but if overheating happens again or you’re unsure, call for roadside assistance. It’s important not to drive an overheating car any further than absolutely necessary.
Q: Can extreme heat damage my car or engine?
A: Yes, extreme heat can strain your car’s components and lead to damage if not addressed. Overheating can cause engine parts (like the cylinder head or gasket) to warp or fail, resulting in expensive repairs. Hot weather also accelerates wear on batteries, tires, belts, and hoses. However, if your car is well-maintained – coolant is topped up, tires are inflated, battery is healthy, etc. – it is designed to operate in a wide range of temperatures. Millions of people drive safely in places like Arizona or Texas where summer highs are well over 100°F. The key is preparation: when parts are worn or fluids are low, extreme heat will expose those weaknesses quickly. So, take care of maintenance, and your car should handle typical heat just fine. If you ever smell something burning or feel the car behaving oddly in extreme heat, get it inspected to prevent potential damage.
Q: Is it safe to drive during a heat wave or should I wait?
A: It can be safe to drive during a heat wave if you and your vehicle are prepared, but caution is advised. If your car is older or prone to cooling problems, or if you don’t have air conditioning, you might consider postponing non-essential trips during the hottest parts of a heat wave. For essential travel, do your vehicle checks (coolant, tires, etc.) before heading out, and plan for possible delays. Bring lots of water for yourself and any passengers. Keep your phone charged and have a plan in case of a breakdown. While modern cars can handle driving in 100°F+ temperatures, driver fatigue and dehydration are real concerns – as is the risk of getting stranded in dangerously high heat. If you start to feel unwell from the heat while driving, find a safe place to stop, get some shade or A/C, and cool down.
Q: Why is it so important not to leave kids or pets in the car on hot days?
A: Because a parked car can turn into an oven frighteningly fast. Even on a moderate 80°F day, the inside of a car can exceed 100°F in 10-15 minutes. On a 95°F+ day, the interior can reach life-threatening temperatures (130°F or more) in mere minutes. Children’s bodies heat up much faster than adults, and they can suffer heatstroke, organ failure, and death in a very short time. Pets are also extremely vulnerable – for example, dogs can’t cool themselves as effectively as humans. Cracking the windows does not stop the temperature from rising to dangerous levels. That’s why you should never leave a child or pet in a car unattended, not even for a quick errand. It’s not safe to rely on “I’ll be right back” – accidents or delays happen. Always take your kids inside with you, and if you have to leave a pet, make sure someone stays with them or find a pet-friendly option. It’s simply not worth the risk. If you ever see a child or animal left alone in a hot car, alert authorities immediately – you could save a life.
Q: Does running the car’s AC in extreme heat strain the engine? A: The air conditioning compressor does put an extra load on the engine, so yes, running the A/C makes the engine work harder – especially in stop-and-go driving or when climbing hills. In most modern cars, the cooling system can handle this under normal conditions, but if the engine is already very hot or something is marginal (like low coolant or a weak radiator fan), having the A/C on could contribute to overheating. That’s why one of the first steps if your car begins to overheat is to turn off the A/C. For everyday driving in heat, don’t hesitate to use the air conditioning – just keep your car maintained. If you know you’ll be taxing the engine (for instance, towing a trailer up a grade in 100°F weather), you might give the A/C a break to reduce the strain. Otherwise, a properly functioning cooling system is designed to handle the A/C load even in summer heat. Your comfort and alertness as a driver are important for safety, so it’s generally worth using the A/C – just be attentive to your engine’s temperature.
Q: What tire pressure should I maintain in hot weather?
A: Always follow the tire pressure recommended by your vehicle’s manufacturer (check the sticker in the driver’s door jamb or the owner’s manual). The recommended pressure is set with all weather conditions in mind. In hot weather, do not intentionally underinflate or overinflate to compensate for temperature – just set it to the recommended PSI when the tires are “cold” (meaning the car has been sitting or only driven a short distance). If you check pressure after driving on a hot day, it’s normal to see a higher reading due to heat expansion, but you shouldn’t bleed out air at that point. Simply re-check and adjust when the tires are cool. Keeping tires at proper inflation is crucial – underinflation is actually the biggest cause of blowouts, especially in summer. Also remember to check your spare tire. And if you live in an area with major temperature swings between seasons, it’s a good habit to check pressures more frequently, as tires can lose a little pressure over time or when the weather changes.
Q: Should I keep my gas tank more full than usual during a heat wave?
A: It’s a good idea, yes. Aim to keep your tank at least half-full during extreme heat. This ensures you have ample fuel if you get stuck in unexpected traffic or need to detour (you might be running the A/C more in those situations, which uses fuel). While today’s fuel systems are sealed to prevent most evaporation, having more gas in the tank can slightly reduce the vapor space and can also be useful if power outages or emergencies temporarily make fuel hard to get (sometimes an issue during natural disasters or extreme weather events). Moreover, your fuel pump (located in the tank for most cars) relies on gasoline to stay cool – running very low on fuel, especially in high heat, could cause the pump to overheat or suck in debris from the bottom of the tank. So keeping your gas tank topped off is a simple way to add a layer of safety during a heat wave.