With heater-related accidents typically spiking as temperatures drop, the National Institute of Technology and Evaluation (NITE) is urging households to inspect their heating devices ahead of winter.

In a safety advisory released Thursday, NITE reported that 582 heater-related incidents occurred between 2019 and 2023, with electric and kerosene heaters involved in over 80% of cases. Incidents typically surged in November and peaked in December, with elevated levels of heater-related accidents continuing through April.

NITE data show that oil heaters were linked to 276 fires, resulting in 56 fatalities and other serious injuries. Many of these fires stemmed from kerosene leaks from fuel caps, followed by incidents of gasoline misfueling and accidental contact with flammable materials.

Electric heaters accounted for 182 incidents, which largely caused property damage. NITE noted that many of these accidents involved recalled products, often due to issues such as wire breakage that led to fires.

In one Tokyo case in February 2022, an electric heater ignited when a man’s coat slipped off his lap and came into contact with the device, sparking a fire that spread to the surrounding area. In another incident in Hyogo Prefecture in September 2021, a blaze that destroyed an entire building is believed to have been caused by laundry falling onto a kerosene heater.

To prevent accidents, NITE advises users to remove dust from air intake vents on oil heaters to prevent backflow and recommends safely disposing of any old fuel. It is also crucial to ensure automatic shutdown features are functioning, especially in earthquake-prone areas.

For electric heaters, NITE emphasized the importance of verifying product recalls, inspecting cords and plugs for wear and confirming that automatic shutoff mechanisms are functional. Given the high power demand of heaters, the agency warns against using extension cords or multiplug adapters.

“The belief that ‘this heater worked last year, so it’s fine this year’ is often the root of most accidents,” NITE cautioned. “Starting the season with thorough inspections — and regular checks — will help ensure a safer winter.”