Quick Answer
Consider turning off your car heater when it's extremely cold outside, and the battery is low, or the engine is overheating, to prevent draining the battery or causing a fire.
Frozen Battery Warning
When stranded in extremely cold temperatures, be aware that your car battery can freeze if the heater is left on. If the battery freezes, it can cause permanent damage and leave you stranded for even longer. A battery can freeze when the temperature drops below -20°C (-4°F), so it’s essential to conserve battery power when it’s this cold.
Engine Overheating Risks
Using the car heater when the engine is overheating can cause the engine to overheat even further, potentially leading to a serious fire. If the engine is overheating, turn off the heater and focus on cooling the engine down as quickly as possible. This can be done by turning off the engine, engaging the parking brake, and using the hazard lights to alert other drivers.
Power Conservation Strategies
To conserve battery power and prevent the battery from freezing, turn off the car heater when it’s extremely cold outside. Instead, use emergency blankets, extra clothing, and the car’s defroster to stay warm. This will help conserve battery power and reduce the risk of a fire. If you’re stranded for an extended period, consider using a portable power source, such as a battery pack or a portable generator, to charge your phone and keep yourself warm.
Find more answers
Browse the full Q&A library by topic, or jump back to the topic this question belongs to.