CHICAGO (NewsNation) — As travel experts anticipate a record-breaking number of travelers this Fourth of July holiday weekend, road trips remain the preferred mode of transportation among Americans.

This weekend, an estimated 50.7 million Americans are expected to travel for the holiday. That number is on track to break the previous travel record from 2019 at 49 million travelers, and is nearly 2.1 million more travelers than last year, AAA reported.

AAA predicted about 85% of those travelers will take a road trip to their holiday destinations, which equals around 43.2 million Americans. Only about 4.2 million Americans are predicted to fly this weekend, according to the report.

However, more than 100 million people across the country have been facing warnings of dangerous, triple-digital temperatures.

Thursday’s soaring temperatures marked yet another day under a deadly, oppressive heatwave across the South. A heat dome hovering over Oklahoma, Texas and Louisiana — and expanding across the states as far as Arkansas, Kansas, Florida and the Great Plains — has shown no signs of abating.

And while scientists said this current summer heatwave is not typical, travel experts said Americans should be prepared for the extreme heat before hitting the road.

Can extreme heat be dangerous for drivers?

Clint Henderson, the managing editor at The Points Guy, said heat is terrible for drivers, and the most important thing when driving through heat is to have air conditioning that works well. Henderson recommended that drivers check the car’s coolant levels before a road trip in order to keep the car’s engine running at optimum temperatures.

Also, to avoid a blowout on the road, Henderson said drivers should check the air pressures and condition of the tires before hitting the road. As temperatures rise, the air pressure in the tires will increase and can cause them to explode, according to Nissan USA.

The heat can also hinder the chemical processes inside a car battery, making it harder for them to produce enough power, AAA reported. Like severe cold in the winter, severe heat can keep a car from starting. When the engine is too hot, AAA said fuel cannot circulate well and will also keep it from starting.

What can drivers do to prepare for a road trip in the heat?

Before families hit the road, the Arizona Department of Safety (AZDPS) suggested drivers plan out the travel route in advance and notify someone of the route, destination and projected arrival time. The department also said it is imperative to fill the fuel tank all the way and try to keep it at three-quarters full.

“Running out of gas — especially in a remote location — is extremely dangerous in extreme heat,” the department’s safety guide said.

Planning additional stops along the way for gas and food can also be beneficial when traveling in remote areas.

It’s also important to check the car’s battery and battery fluid to make sure it’s up to par. AZPDS recommended getting the car’s coolant flushed and replaced before taking trips, as well as topping off vital engine fluids such as motor oil, transmission fluid, brake fluid and power-steering fluid.

What should folks keep in vehicles in case of emergency?

Travelers should also stock their cars with necessary equipment and survival tools, especially in the event of an emergency.

“Keep a portable fan, extra water, sports drinks and snacks in the summer. Also, you should have jumper cables, flashlights, road flares, more water and a first aid kit in the car,” Henderson said.

Here’s a list of additional items that travelers should keep in their car, provided by AZDPS:

• A cooler to keep drinks cold (AZDPS suggested keeping frozen bottles of water to use for cooling off or to thaw and drink if needed)
• An umbrella for shade
• Sunscreen
• Hats, sunglasses and loose-fitting, light-colored clothing
• Any necessary medications
• Extra batteries for flashlights
• A travel tool kit
• Extra radiator water
• A road map
• A portable phone charger
• A roll of toilet paper or tissues

The department also warned to never drive in extreme heat without a fully-charged phone and extra drinking water for all passengers and pets. It’s imperative that travelers and pets remain hydrated.

What should drivers do if the car doesn’t have air conditioning?

“I personally wouldn’t drive during extreme heat without air conditioning,” Henderson said.

If the car’s air conditioning isn’t working or goes out, roll down all the windows.

The AZDPS explained that without air conditioning, the temperature inside the car can quickly rise to dangerous, and even deadly, levels. The department suggested that if the car’s temperature becomes too hot, passengers — including pets — should exit the vehicle and find a shaded area as far away from travel lanes as possible.

Hydration is also key, Henderson said.

“You sometimes don’t even know if you are dehydrated and it can sneak up on you. So drink tons of water,” he said.

What should travelers avoid when traveling in extreme heat?

One of the most important things to remember is to not leave kids or pets in the car, especially during the heat, Henderson said.

Car interiors can reach dangerous temperature levels quickly in warm weather, according to a AAA traffic safety guide. Leaving a person or animal in a car could cause permanent injury or even death, the guide said.

If travelers find themselves stuck or stalled in their vehicles, AZDPS suggested remaining hydrated and staying in air conditioning. If the car breaks down, or there is an emergency, call for assistance right away. Once help is on the way, carefully raise the hood of the vehicle and turn on flashing hazard lights, AZDPS said.