Is Car Heater Bad For My Health? (8 Preventive Measures)

What is the first and most common thing you normally do when you get inside your car during winter or colder season? You usually turn on the car heater to get warmth, right?

Some may even forget and sleep while their car heater is on.

There is nothing wrong with using your heating system. However, using it inappropriately may have some negative health implications.

Doctors even advise that a car heater should not be your only solution to curb cold inside the car, linking this with your overall well-being.

So, is a car heater bad for your health? Let’s find out.

Is the Car Heater Really Bad For my Health?

A car heater is bad for your health when you use it incorrectly. It becomes really dangerous to your overall well-being. Most people usually turn the car heater on during cold weather or winter to get some warmth while driving. However, by constantly running on your car heater, you subject yourself to various health risks.

Car heater and front vents
Car heater and front vents

Below are some of the health risks caused by the inappropriate use of car heaters:

Making the Inside Car Air Toxic Leading to Suffocation

Some car heaters usually release carbon monoxide if the car is not well-ventilated. For people who sleep in a car while the car heater is on, this can be dangerous and even hazardous to their health.

You will end up inhaling excess carbon monoxide, leading to suffocation and death. Moreover, constantly turning on the car heater may lead to respiratory problems like allergic irritation and asthma.

Breathing Dry Air

Winter season is usually harsh, but when you put the car heater on for an extended period, it can deplete the moisture content in the air. It will cause air dryness in your car and even lead to health problems on your skin.

Your skin will become itchy and reddish because the dry air will evaporate moisture from the skin.

Since the air is dry, breathing becomes difficult and results in respiratory complications like bronchitis, asthma, and even nosebleeds because of dry membranes. The dry air makes the mucus membranes dry when they are usually moist, which makes the membranes trap dust and other infection-causing agents, resulting in inflammation.

The inflammation of the membranes makes your immune system weak and more prone to infections because the mucus membrane is damaged.

Inadequate moisture in the air also evaporates tears from your eyes. It will then make the eyes have a challenge in regulating the delicate balance needed for healthy and moist eyes.

Change in Temperature Making Your Immune System Weak

It usually feels great when you are in a warm car. But when you get out, you find out that the outside environment is cold. Eventually, you end up exposing your body to temperature fluctuation.

The immediate temperature alteration can always weaken the immune system, causing sickness.

Can Cause Burns

Your car heater is not exempted, just like any other electric component that can cause shock. The reason why it’s vital to note it here is that your heater draws a very high amount of current. So, when a shock occurs, it may cause electrical burns to your body and other health complications.


Is It Safe to Sleep in a Car with the Heater On?

car sleep with heater on
car sleep with heater on

No, it is not safe. Nowadays, cases of sleep death (asphyxia) are common, and one of the causes is sleeping while the heater is on. When you want to sleep in a car with the heater running, your safety should come first in your mind.

Sleeping while the car heater is on and you have closed all the windows increases the amount of carbon monoxide above the level you can withstand. It usually happens that the same air inside your car will be recycled many times, and you will end up inhaling an odorless and colorless poisonous gas.

The excess carbon monoxide in your car will then hinder blood supply to the brain and other body parts, leading to hemorrhages. When the amount of carbon monoxide goes beyond 70parts per million (PPM), a person usually experiences nausea, headache, and general fatigue.

But when the amount shoots to 150 and 200PPM, a person can faint and die if not attended to too quickly. You will also realize that people with heart complications may start experiencing chest pain under the same circumstances.

It may be risky for smokers suffering from heart disease, the elderly, and young children to sleep in cars with car heaters running.

Can a Car Heater Kill You if Used for Elongated Time?

If you use it correctly, a car heater can’t kill you. However, sleeping in a car while the heater is on can lead to death. This happens when the levels of carbon monoxide are in excess, and your body can’t take it. You will end up suffocating, and some will even die.

Always ensure your heating system is in good shape and working well to avoid electric shock, which may harm you. Check the thermostat, fan motor, heater core, and other systems to ensure they are working coherently together for you to get the best and avoid malfunctioning.

What are Some of the Preventive Measures I Can Take While Using a Car Heater?

Volkswagen Passat front vents
Volkswagen Passat front vents blowing air

Here are some preventive measures you can take while using your car heater. Have a look.

1. Insulate Your Car

Apart from using a car heater, you can insulate your car. Insulating your car will make it stay cooler in summer and warmer in winter. If you are probably looking forward to sleeping inside your car regularly, you can get some insulative materials to make your window covers.

Partition the materials equivalent to the shape of the car windows. Afterward, stitch them on the windows with the help of suction cups.

If you want an easy and quick solution, place your car’s windshield sunshade at the front of the car. The most amazing thing about the shade is that it will prevent your car from heating up during morning hours.

2. Make a Crack in the Window

While using your car heater, heat may increase over time, making you uncomfortable. So, your car windows can be beneficial.

Make a crack in the window for the hot or dry air to escape. The crack helps you have fresh and adequate airflow to breathe properly.

An open window may also be helpful when you have carried more passengers. Excess water vapor is directed to the cabin as they exhale, causing the windows to fog up. By you making a crack, you will make the windows clear.

3. Don’t Put the Heat Too High

If your car is made of an automatic heater, you can set it to a good temperature that can’t harm you.

Setting high temperatures will just put yourself and your passengers at risk. Remember to switch off the heater when you have acquired the right temperature.

4. Keep the A/C On

An A/C is usually used to regulate the temperature inside your car and give you a cool environment. Even if you desire warm air from the heater, your A/C will cool the upcoming air from outside, and then your heater will reheat it before it enters the cabin.

5. Assist the Backseat Passengers

You, as the driver, may be comfortable with the amount of heat you have set, but this may not be the case for passengers at the back.

The airflow might not be enough, and the heat might be high. To help them, turn the temperatures slightly lower to help everyone stay comfortable.

6. Always Practice Regular Maintenance on Your Car Heater

Your car heater is a combination of components, including the thermostat, blower fan, and heater core which you can find under the dashboard. Every time the system has a minor issue, you can address it immediately to avoid inconveniences and accidents.

Regular maintenance ensures the car heater is clean and works on the recommended levels. You can also check if the hoses and belts are in good shape. It helps the system to work in harmony and order.

Also, check if there are any leaks and blockages, you will be able to deal with them much easier if you discover them early.

7. Park Smart

When parking your car, ensure you park somewhere with a good breeze. Try packing in a shaded area to make the heater, not to overwork.

If you park away from a shaded area, your car will end up heating when the amount of sun rises, contributing to hotter conditions.

8. Take a Cold Drink While in the Car

If you are experiencing high temperatures in the car, you can take sips of cold water to keep you hydrated.

Other preventive measures you can take include:

  • Use a vaporizer or humidifier to increase moisture content in the car.
  • Keep drinking hot or warm fluids like teas or soups to keep the airways, nasal passages, and throat moist.
  • You can also get natural moisturizers to keep your skin healthy and hydrated.


A car heater will serve you better when you use it appropriately. Sleeping while your car heater is on can be dangerous to you and your car. However, if you have to sleep inside your car, always turn off the heater before you sleep to avoid excessive carbon monoxide consumption and other health risks.

Last but not least, a car heater is essential in your life. It helps you keep warm and feel comfortable inside the car.

You only need to practice caution and follow the tips provided in this article to get the best out of your heater and avoid damage. Always remember, your health comes first, more than anything else.


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