What it is
Electric blankets go over you; heated mattress pads go under the sheet and warm you from below, with nothing heavy on top. Modern ones use thin wires, thermostats and auto-off timers, and some run on low voltage through a transformer. Dual controls let partners set different levels.
A sensible way to use one is to warm the bed beforehand and switch it off or right down when you get in. A warm bed helps you settle, but your body needs to cool to stay asleep.
How strong is the evidencenone
No trials show heated blankets improve sleep. Two older prospective studies of electric-blanket use in early pregnancy found no consistent link with miscarriage (one saw a small, non-significant increase with use around conception). Burns from heating pads and blankets are well documented in people with reduced sensation, such as diabetic neuropathy.
The claims you’ll meet3 checked
A heated blanket helps you fall asleep fasterUnprovenPre-warming the bed is comfortable, but no trials show a sleep benefit.
Low-EMF or DC designs are healthierUnprovenThere's no good evidence that the weak magnetic fields from electric blankets harm health. Low-voltage designs are a reasonable electrical-safety choice, not a proven health one.
Safe to leave on all nightMixedOnly if the maker says it's designed for overnight use, on a low setting with working overheat protection, and never for people who can't feel heat or turn it off.
What to look for5
- ✓A recognised safety certification, such as UL or ETL in the US or your country's equivalent.
- ✓Overheat protection and an auto-off timer.
- ✓Dual controls, and a detachable controller so you can wash it.
- ✓A heated mattress pad if you want warmth without extra weight on top.
- ✓Low settings that are genuinely low for overnight use.
What to skip2
- ×'Zero-EMF' and other health claims.
- ×'Therapy' marketing for aches and pains beyond ordinary warmth.
How to use it1
- →Switch it on 20-30 minutes before bed, then turn it off or to the lowest setting when you get in.
Take care6
- !Don't use one if you can't feel heat properly or can't switch it off yourself: diabetes with neuropathy, spinal injury, paralysis, some older adults, or after sedating medicines or alcohol.
- !Never for babies or young children, and never on a baby's bed.
- !In pregnancy, to be cautious, warm the bed first and switch it off before you get in, to avoid overheating.
- !Fire safety: don't fold, bunch or tuck it in while it's on; don't use it with a hot-water bottle, or on an adjustable bed unless the maker allows it; unplug it when not in use.
- !Check it before each winter and replace it if wires show, the fabric is scorched or frayed, or the controller is damaged.
- !Don't use one where there is bedwetting or incontinence. Water and wiring don't mix.
The studies3 cited · checked against PubMed
Spontaneous abortion and exposure to electric blankets and heated water beds ↗Belanger K, Leaderer B, Hellenbrand K, Holford TR, McSharry J, Power ME, et al. · Epidemiology · 1998Prospective cohort
2,967 pregnant women. Electric blanket use around conception had a slight, non-significant association with miscarriage after adjustment (OR 1.74, 95% CI 0.96-3.15), with no dose-response; heated water beds showed no link.
The use of electric bed heaters and the risk of clinically recognized spontaneous abortion ↗Lee GM, Neutra RR, Hristova L, Yost M, Hiatt RA · Epidemiology · 2000Prospective cohort
Women using electric bed heaters in the first trimester did not have higher miscarriage rates than non-users, and risk did not rise with more intense use; the magnetic fields added less overnight exposure than had been assumed.
Electric heating pad burns ↗Bill TJ, Edlich RF, Himel HN · Journal of Emergency Medicine · 1994Case report
Two patients with numb skin suffered partial- and full-thickness foot burns from an electric heating pad; the authors stress that people with sensory loss are especially prone to these burns.