Heated blankets provide a comfortable and welcoming warmth that many people enjoy during colder months. This popular bedding item contains internal wires that safely warm the fabric when plugged into an electrical outlet, offering a cozy solution to a cold bed. While the allure of sleeping wrapped in continuous warmth is strong, the primary question for users is whether the device can be safely left on all night long. The answer involves considering both the electrical safety of the appliance itself and the physiological effects of prolonged heat on the human body during sleep.
Safety Protocols and Electrical Concerns
The most immediate and practical concerns when using a heated blanket revolve around its electrical operation and physical integrity. To ensure safety, a heated blanket should always carry a certification mark from a nationally recognized testing laboratory, such as Underwriters Laboratories (UL) or Intertek (ETL). Modern blankets often include automatic shut-off timers and overheating protection, but these features should not be the sole reliance for all-night use. Users should turn the blanket off or unplug it when leaving the bed or the room.
The physical placement of the blanket and its cords requires careful attention to prevent hazards. The blanket must be laid flat, avoiding folding, bunching, or tucking in the edges, which can cause the internal wires to overheat by concentrating the heat. Electrical cords should never be run between the mattress and box spring, nor should they be pinched by bed frames or furniture, as this can fray or damage the wiring. Furthermore, heated blankets should always be plugged directly into a wall outlet, as using extension cords or power strips may pose an overheating risk.
Physiological Effects on Sleep
Continuous external heat from a blanket can interfere with the body’s natural thermoregulation process, which supports healthy sleep cycles. The initiation and maintenance of sleep are closely linked to a slight decrease in core body temperature, which typically drops overnight. By constantly supplying heat, a heated blanket may inhibit this natural cooling process, causing the internal core temperature to remain slightly elevated.
Studies have shown that an increase in core temperature, even by a small margin, can decrease sleep efficiency and increase the amount of lighter sleep stages. This disruption can lead to more fragmented sleep, evidenced by an increase in stage changes and the amount of Stage 1 sleep. While some research suggests a heated environment may decrease cold stress, excessive heat can prevent the body from reaching the optimal thermal state for restorative deep sleep. Prolonged exposure to heat can also lead to minor dehydration from increased perspiration.
Medical Conditions That Prohibit Use
For certain individuals, the use of a heated blanket is particularly risky due to an impaired ability to sense or respond to overheating. Individuals with peripheral neuropathy, often associated with diabetes, have reduced sensation in their extremities. This nerve damage means they may not feel the blanket becoming too hot, increasing the danger of severe burns. The prolonged heat exposure can also worsen existing skin conditions or compromise skin integrity.
People who have limited mobility, such as those with extreme frailty, paralysis, or those heavily sedated or intoxicated, should also avoid sleeping with a heated blanket on. Their inability to easily move away from the heat source or adjust the controls prevents them from reacting to a dangerous thermal situation. Infants and young children are also advised against using heated blankets because their bodies are less efficient at regulating temperature, making them highly susceptible to overheating. Pregnant individuals are generally advised to avoid raising their core body temperature above 101 degrees Fahrenheit, so using a heated blanket on a low setting or only for pre-warming the bed is the safest approach.
Extending the Lifespan of Your Blanket
Proper maintenance and storage are essential for ensuring a heated blanket remains safe and functional over its expected lifespan of five to ten years. Most modern blankets are machine washable, but cleaning requires careful adherence to the manufacturer’s instructions, typically involving a mild detergent and a gentle, cold-water cycle. Before washing, the control unit and power cord must be detached from the blanket to prevent damage to the electrical connections. The blanket should always be air-dried completely, as placing it in a clothes dryer can damage the internal heating elements.
When storing the blanket for the off-season, it should be rolled loosely instead of folded tightly. Sharp folds can create creases that damage and break the internal wiring, which compromises the blanket’s ability to heat evenly and poses a fire hazard. The blanket should be stored in a dry, dust-free location, and no heavy objects should be placed on top of it.
Regular inspection for signs of wear is also necessary. The blanket should be retired immediately if any of the following are observed:
- Frayed cords.
- Scorched spots.
- Visible wire damage.
- Controls that flicker or buzz.