Yes, space heaters can make you sick, largely due to how they affect indoor air quality. The specific risks and symptoms depend on the type of heater you are using.
Space heater "poisoning" typically refers to carbon monoxide (CO) poisoning, which occurs when fuel-burning heaters (propane, kerosene, or natural gas) burn incompletely or are used in poorly ventilated areas. CO is a colorless, odorless gas that prevents your blood from carrying oxygen, causing suffocation from within.
Running a space heater can cause allergy-like symptoms, headaches, or nausea. This "heater sickness" is primarily caused by burning off accumulated dust, drastically dropping the room's humidity, or unsafe gas emissions.
Space heaters are generally not bad for your health, but they pose significant fire and air-quality hazards if used improperly. The most immediate risks stem from skin and respiratory irritation, accidental burns, and the production of toxic fumes.
Toasted skin syndrome, also called erythema ab igne, is a skin condition that comes from repeated and prolonged exposure to low levels of heat and occasional repeated high levels of heat. The heat is warm enough to damage your skin over time.
It takes time for your home to warm up and cool down. If you're not sure how long it takes, try turning the heating on about 30 minutes before you need it. You should turn it off 30 minutes before you'll stop needing it.
The general consensus from fire and safety experts is no, you should not sleep with a portable space heater on. Leaving one running unattended overnight poses a severe fire hazard, significantly increasing the risk of house fires, burns, and carbon monoxide poisoning if you use fuel-burning models.
The biggest threat associated with space heaters is fire. In fact, each year space heaters are responsible for about 55,000 fires, 450 deaths, and more than 1,500 injuries.
Broadly, heat pumps are the most efficient form of heating. They can be more expensive than a furnace, especially if you purchase a geothermal heat pump. However, geothermal heat pumps are one of the cleanest heating options on the market. A geothermal heat pump can produce 1/6th the CO2 of a natural gas furnace.
Keep space heaters at least 3 feet away from flammable items and objects, such as papers or curtains. Avoid leaving a space heater unattended for long periods of time, especially around children and pets. Place space heaters on low, flat surfaces – preferably on the floor.
Remove dust, soot, or debris from around your heater and vents. Swap out or clean your air filter if you haven't done so in a while. If you want to go the extra mile, switch to a HEPA air filter, which removes up to 99.9% of all indoor contaminants.
Heat sickness occurs on a spectrum ranging from mild cramps to life-threatening heatstroke. Symptoms typically include heavy sweating, intense thirst, nausea, dizziness, and muscle cramps. Immediate first aid involves moving to a cool place and drinking water. Call 911 if confusion, seizures, or unresponsiveness occur.
Nitrogen dioxide can irritate the skin and the mucous membranes in the eyes, nose and throat. Depending upon the level and duration of exposure, respiratory effects range from slight irritation to burning and chest pain, coughing, and shortness of breath.
Yes, a space heater can cause uncomfortable symptoms and even serious health hazards if not used correctly. The most common issues range from poor air quality and carbon monoxide poisoning to skin irritation.
Two common warning signs of carbon monoxide (CO) poisoning are dizziness and a dull, throbbing headache.
The safest space heaters for your home are oil-filled radiators and enclosed infrared heaters. Because they heat via convection or radiation without an exposed glowing element, they maintain lower exterior surface temperatures, making them much safer around children and pets.
Because they do not use standard grid electricity or conventional electric and gas furnaces, the Amish heat their homes using off-grid, self-reliant methods. The most common systems include wood- or coal-burning stoves, propane and kerosene heaters, and natural airflow home designs.
If your electric heater is causing dizziness, you should immediately turn it off, unplug it, and get to fresh air. Dizziness can be a sign of oxygen depletion, the buildup of toxic gases, or off-gassing from a malfunctioning or brand-new appliance.
The safest indoor heating methods are electric space heaters—specifically oil-filled radiators or ceramic heaters with safety certifications (UL/ETL listed)—because they lack open flames or glowing elements, reducing fire and carbon monoxide risks. For whole-home safety, permanently installed systems like electric baseboards or heat pumps are superior.
Key points about carbon monoxide poisoning
A common source is unvented space heaters. Symptoms of CO poisoning include headache, dizziness, weakness, nausea and vomiting, rapid heartbeat, shortness of breath, seizures, chest pain, disorientation, and loss of consciousness.
Space heaters are generally not bad for your health, but they pose significant fire and air-quality hazards if used improperly. The most immediate risks stem from skin and respiratory irritation, accidental burns, and the production of toxic fumes.
For long-term comfort and safety, baseboard heaters are best. For quick, flexible warmth, space heaters can help — just handle them responsibly. Stay warm, stay safe, and heat smart this winter!
Use space heaters on the floor. Never place space heaters on furniture, since they may fall dislodging or breaking parts in the heater, which could result in a fire or shock hazard. Do not use heaters in wet or moist places such as bathrooms, as parts in the heater may be damaged and a fire or shock hazard may result.
While the exact statistical probability of a space heater catching fire on any given day is very low, heating equipment is the second-leading cause of home fires in the United States. Portable space heaters are involved in about 1,600 house fires and cause dozens of fatalities every year.
It is not safe to run a space heater overnight. If you use an electric or propane space heater during the day, make sure to protect yourself and your home by following all safety practices. Use space heaters that automatically turn off if they tip over.