Are Space Heaters Bad For Your Health?

Are space heaters bad for your health? 

Are space heaters dangerous? 

Both are questions that pop up fairly often.

The answers to both are yes, no, and maybe.

Let’s break it down and clear the air, so you know which answer applies to your circumstances.

Are Space Heaters Bad for Your Health? Yes.

Yes, that’s right. 

Sometimes that space heater is terrible for your health.

Your space heater needs to be installed or fixed

This is going to depend on what type of space heater you have. 

If you have something that runs on natural gas or kerosene, it can release a lot of carbon monoxide into the air.

If you experience the following symptoms when using a fueled space heater, stop using it immediately. If your symptoms progress, you should seek medical attention immediately.

  • Chest pain
  • Disorientation
  • Dizziness
  • Headache
  • Loss of consciousness
  • Nausea
  • Rapid heartbeat
  • Seizures
  • Shortness of breath
  • Vomiting
  • Weakness

Your space heater is vent-free

Any space heater that’s unvented—or vent-free—can lead to CO poisoning. 

This is any type of heater that doesn’t have a chimney.

The lack of a chimney means all combustion gases discharge into your home instead of outdoors. 

Depending on the type of fuel and burner technology, combustion gases can release several toxic substances, including, but not limited to:

  • Carbon monoxide 
  • Hydrogen oxides
  • Sulfur oxides
  • Unburned hydrocarbons
  • Polycyclic aromatic hydrocarbons

Some examples of vent-free space heaters are:

  • Certain wall-mount fireplaces 
  • Gas stove fireplaces 

Your room isn’t properly vented.

Fireplaces are just one concern. 

Using a small portable space heater that runs on any fuel can release carbon monoxide.

You’re using a heater to heat a room, so it’s unlikely you have a window open. 

But a lack of ventilation, in conjunction with a fueled heater, can lead to various respiratory problems, allergies, and other diseases.

Sleeping in an unvented room using a propane or gas heater is particularly dangerous.

Space heaters can reduce indoor relative humidity.

This one applies even if you’re using an electric space heater.

Here’s a bit of a science lesson. 

When the heater warms the air in the room, it increases the air’s capacity to hold moisture. 

If you don’t have a source of moisture running—such as a humidifier—at the same time, the relative humidity drops. 

Meaning your air is getting drier.

The relative humidity is the amount of water the air is holding compared to how much it can.

Is low indoor humidity such a bad thing? 


It can damage your eyes, your skin, and your respiratory tract. 

A lack of moisture will irritate your eyes, making your skin flaky and itchy. 

It also dries out and inflames the mucous membrane that lines your respiratory tract. 

This increases the risk of colds, the flu, and other infections.

Low humidity also causes viruses to linger in the air longer, and these days, none of us want to be anywhere where there’s a virus hovering in the air around us.

Some studies also show that a lack of air humidity can hurt our performance and productivity.

Are Space Heaters Bad for Your Health? No.

Sometimes, space heaters are bad for your health, but at other times they’re not.

There is a lot of misinformation and disinformation floating around the internet regarding different kinds of space heaters.

Infrared heaters do not give you cancer.

Despite what some claim, you don’t have to worry about your infrared space heater giving you cancer. 

Apparently, since these heaters operate by producing radiation, some assume they’re a cancer risk. 

However, studies have proven that infrared radiation won’t cause cancer since it’s non-ionizing.

Do not confuse (UV)ultraviolet rays or x-rays with infrared. 

Both UV and x-rays are carcinogenic. 

They can cause cancer cells to grow, resulting in skin cancer. 

This is the result of ionization, and as stated above, infrared isn’t ionizing.

Are Space Heaters Bad for Your Health? Maybe.

There are no definitives in the maybe category.

Electric space heaters probably aren’t bad for your health.

Since there’s no fuel in an electric heater, you don’t have to worry about toxic fumes or carbon monoxide poisoning. 

However, that’s not to say they’re entirely danger-free.

An electric heater will suck the moisture out of the air like any other heater.

It may be a good idea to run a humidifier using a space heater. 

As mentioned above, dry air can cause the following problems.

  • Dry, irritated eyes
  • Flaky, itchy skin
  • A dry, inflamed respiratory tract can lead to an increased risk of colds and cases of flu
  • Viruses live in linger longer in dry air
  • Performance and productivity can be negatively impacted
  • Nosebleeds
  • Sinus problems

Space Heater Hazards

Regardless of what kind of space heater you use, there are some hazards to be aware of.

While there are some cool-to-touch space heaters, they will be hot to touch in many cases. 

This is potentially hazardous to anyone in the home, especially young children and pets.

You should also never operate any heater near flammable materials, chemicals, or vapors. 

You also need to be careful not to block airflow. 

Always check your space heater’s manual for the manufacturer’s recommendations on where to place the heater from furniture and walls.

Generally, no space heater should be less than 3 feet from flammable objects.

Typical flammable objects found around the home include:

  • Cooking oil 
  • Dryer lint
  • Hand sanitizer
  • Mattresses
  • Most laundry products
  • Nail polish, nail polish remover, and many beauty products
  • Rubbing alcohol
  • Some draperies

Slim, your space heater will be near your cooking oil or dryer lint.

But many people have a space heater in their bedroom or bathroom—near your mattress or beauty products. 

Is your space heater 3 feet away from danger? 

If not, third-degree burns would be horrible for your health.

The Different Types of Space Heaters: Pros and Cons

We’ve talked about a few different types of space heaters in this article.

Let’s briefly discuss the pros and cons of each type regardless of their impact on your health.

Gas Space Heaters Pros

Fuel-operated space heaters produce the highest heat output— often at the lowest cost.

They operate much like infrared space heaters in that they heat the objects in a room instead of the air.

Gas Space Heaters Cons

As detailed above, fuel-operated space heaters can emit harmful carbon dioxide.

You typically spend more on a gas heater when compared to an electric heater, and there’s an array of features you should look for.

Ensure your gas heater has a low oxygen sensor, overheat protection, automatic shut-off, and high-temperature safety guards. 

All of these things add to the cost.

Infrared/Radiant Space Heater Pros

Like gas-powered heaters, infrared heaters heat bodies and objects instead of the air. 

This typically means that you’ll feel the heat immediately. 

These are excellent options for smaller rooms or rooms with high ceilings.

If you have children or pets in the home, these heaters are often the best choice since they stay cool to the touch.

Infrared heaters offer superior efficiency.

Infrared/Radiant Space Heater Cons

To enjoy the heat of an infrared heater, you must place it within a direct line of your seating area.

Final Thoughts

As you can see from above, while some space heaters may be worse than others when it comes to your health, others will have little to no impact.

Heaters that use kerosene, gas, wood, or oil come with the threat of releasing carbon monoxide or carbon dioxide.

Both of which are carcinogenic, meaning they can give you cancer. 

They can also trigger a host of other symptoms.

Electric space heaters may be relatively healthy, but they still cause the humidity in your home to drop.

And lack of humidity is known to cause health issues.

And if your concern was whether infrared heaters cause cancer, that’s not true.

Regardless, with the proper ventilation and/or humidifier, no space heater should cause any serious problems. 

And for additional security, consider getting a CO2 air quality monitor if you don’t already have one.

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