Officials in New York City say a fire that swept through an apartment building in the Bronx on Sunday and left 17 people dead was caused by a malfunctioning space heater.

The tragedy serves as a grim reminder that the small portable heaters can be convenient, but, when used improperly, can also be extremely dangerous.

Newer models come with added safety features, but they’re still responsible for about one-third of all home fires according to Consumer Reports, which is why they should never be used unattended.

“We run a series of safety tests to identify heaters that may pose a burn risk. The safest space heaters shut off automatically if they become too hot or if they're knocked over," said Paul Hope with Consumer Reports.

Because space heaters are only used a few months a year, you could have one that is 10 or 20 years old, but older space heaters won't have the latest safety features like an automatic shut off function and alarm if they get too hot or tip over.

When choosing a space heater it also depends on the job you want it to do.

“You need to consider if you just want to warm yourself up or are you trying to heat the entire room. Our tests have found not all models do both well,” said Hope.

When it comes to space heater safety, always keep space heaters one metre away from anything flammable. You should never use an extension cord and always plug the heater directly into a wall outlet and never leave space heaters operating unattended.

According to tests by Consumer Reports, a convection heater with a fan can heat a small space quickly and efficiently and they’re recommended for workshops and offices.

An oil filled radiator heater is quiet, but can take much longer to heat rooms and is best for living and bedrooms. Radiant heaters produce heat instantly, but have limited range and are best for workshops and garages.

Baseboard heaters are quiet and are able to heat large spaces such as basements and family rooms.

Now is a good time to make sure your smoke detectors are working properly and if you don’t have one consider getting fire extinguishers for your home.

Fire officials say the best ones to have are multi-purpose that can extinguish different types of fires.

"Generally in a home you want to have the most common type of fire extinguisher that will put out the three most common type of fires which are trash, wood and paper, liquids and electrical fires," said Alider Pratts, a fire and safety expert.

Pratt advises that you should make sure the fire extinguisher is fully charged and take a moment to read the instructions so you'll know how to use it if you have to.

As for space heaters, while they can help warm up a cold room, even the best ones can only do so much.

If you're using one in a bedroom as well as keeping it away from drapes and bedding, it should always be shut off before you go to sleep.