# Electric blanket and heated mattress pad

> A resistive heating element in direct body contact for eight hours: among the highest whole-night ELF magnetic exposures in a home unless the element is low-field wound or switched off before sleep.

- Canonical URL: https://emfbase.com/emitters/electric-blanket
- Collection: Sources & emitters
- Record id: `emitters:electric-blanket`
- Status: verified
- Last verified: 2026-08-12
- JSON: https://emfbase.com/api/emitters/electric-blanket
- Also known as: heated blanket, electric underblanket

## Key values

- **Category:** elf magnetic
- **Emission bands:** Power frequency
- **Environments:** home
- **Duty cycle:** Thermostat cycling; the field appears only while the element draws current.

## Field strength by distance

- **2 cm:** 5–100 mG — Measured range — Range reported for legacy resistive elements at body-contact distance; low-field ('dual-wound') designs measure substantially lower. [niehs-emf]
- **30 cm:** 0.5–10 mG — Measured range — Typical range at 30 cm. [niehs-emf]

## Mitigations, most effective first

- **Pre-heat the bed and unplug the blanket before getting in.** — Removes the exposure entirely while keeping the benefit.
- **Choose a low-field dual-wound element if the blanket must run overnight.** — Counter-wound elements cancel most of the external field.

## Measure with

- ELF gaussmeter (power-frequency magnetic field)

## Related records

- [Building Biology SBM-2024 AC magnetic field bands](https://emfbase.com/limits/building-biology-ac-magnetic-bands): Sleeping-area grades at 50/60 Hz: below 0.2 mG no anomaly, 0.2–1 mG weak, 1–5 mG strong, above 5 mG extreme.

## Sources

- `niehs-emf` National Institute of Environmental Health Sciences. *Electric and Magnetic Fields*. https://www.niehs.nih.gov/health/topics/agents/emf — government, link checked 2026-08-12

Data licence: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Dataset version 2026.08.1. Retrieved from EMFBase, https://emfbase.com.

This record is reference data, not medical or legal advice. Regulatory limits, scientific guidelines and precautionary values are labelled separately and answer different questions.