A few degrees drop in temperature will be enough to turn a room from comfy to chilly. Then an oil-filled radiator might be a good solution to fight the chill. These small, efficient, quiet appliances take off the edge and add cozy warmth right where you need it.

Oil-filled radiators are electric space heaters that work the way like traditional convector heaters. Heated liquid inside a metal housing releases warmth out into the room without a fan or blower. Electricity is used to warm the oil, but since oil is slow to lose heat, the unit only switches on occasionally to keep the liquid at the right temperature.

Although oil-filled heaters don’t glow red like some space heaters, they still get very hot. Keep the unit several feet from all combustible materials, including draperies, furniture and wall. Small children and pets also need protection from accidentally touching the hot metal surface. Some radiators have a guard, but many have none. Manufacturers usually warn against keeping an oil-filled radiator in damp areas such as bathrooms with poor ventilation. If a unit is safe for bathrooms, it still must be kept far from water sources such as the shower and sink. These radiators are slow to heat up, which makes it tempting to leave one unattended. This is unwise, as any space heater poses a fire risk.

Oil-filled radiators are capable of warming a whole room, but they shouldn’t replace a main heating system in extremely chilly winter. Select the right size heater for the space where you’ll use it. A too-small unit works twice as hard as a larger one in a big space. Instead of placing radiators all over the house, use them to boost the temperature in areas where you spend most of the time. Setting the thermostat on a furnace or other forced-air heat system near 68 degrees takes some of the load off the main system, and one or more radiators make up the difference only in the rooms where you need it. In rooms with a ceiling box fan, reversing the direction that the blades turn pushes heated air back down from the ceiling.