Heated jackets use a low-voltage battery to power thin, flexible heating elements, often made of carbon fiber or micro-alloy fibers, integrated into the garment. These elements are typically concentrated in core areas like the chest and back. The primary function is to convert electrical energy into heat through resistance, similar to a small electric blanket. This technology raises questions about the potential health and safety implications of wearing an active electrical device close to the body.
Understanding Immediate Safety Risks
The most direct safety concerns involve physical hazards related to the jacket’s electrical components and heat production. Burns, which can occur if heating elements become too hot or are in prolonged, direct contact with the skin at high settings. Although modern jackets incorporate safety features like automatic shut-off systems and temperature regulators, improper use can still result in low-temperature burns after extended periods.
Electrical hazards primarily stem from the use of lithium-ion batteries and internal wiring. Heated jackets operate at low voltages, typically between 5V and 12V, which is well below the human safety threshold of 36V. However, a risk of short circuits or electric shock exists if the components are damaged. Battery failure presents a more tangible threat, as lithium-ion cells can overheat, leading to a fire hazard if the battery is faulty, overcharged, or physically compromised.
Mitigating these immediate risks relies heavily on product quality and certification. Purchasing jackets from reputable manufacturers who adhere to safety standards, such as UL or CE certification, helps ensure the garment has been rigorously tested. Users should only use the charger supplied by the manufacturer and regularly inspect the jacket for signs of wear, such as frayed wires, to prevent a malfunction.
Assessing Electromagnetic Field Exposure
Heated jackets generate electromagnetic fields (EMF) because they carry an electrical current through the heating wires. This emission is in the form of extremely low-frequency (ELF) non-ionizing radiation, which differs from the high-energy ionizing radiation associated with X-rays. The field strength dissipates rapidly and is typically low because the jackets are powered by a low-voltage direct current (DC) battery.
The magnitude of EMF exposure from heated apparel is generally minimal compared to many common household devices. Heated jackets often produce EMF levels between 1 to 4 milligauss (mG) next to the body. This is significantly lower than the 1000 mG exposure limit recommended by international safety guidelines.
The current scientific consensus, supported by organizations like the World Health Organization (WHO), suggests there is no confirmed evidence of adverse health consequences from exposure to these low-level electromagnetic fields. The levels produced by heated clothing do not pose a substantial cancer risk to the general population.
Using Heated Jackets With Preexisting Medical Conditions
While heated jackets are considered safe for the majority of healthy users, specific medical conditions or implanted devices require greater caution. Individuals with implanted electronic medical devices, such as pacemakers, ICDs, or neurostimulators, must be aware of the potential for electromagnetic interference (EMI). The small electromagnetic fields generated by the heating elements and battery pack can potentially disrupt the device’s function, especially if placed close to the implant site.
Most modern cardiac implants have shielding against small EMFs, and some manufacturers list heated clothing as safe when used as directed. Regulators often advise keeping consumer electronics and magnets, which may be included in the jacket’s battery or closure, at least six inches away from the implant site. Consultation with a cardiologist or pacing clinic is crucial to determine the safety of a specific model based on the individual’s device type and placement.
Another significant risk applies to individuals with sensory impairments, such as peripheral neuropathy often associated with diabetes. A reduced ability to sense temperature means a person may not register when the jacket is overheating or causing a burn, increasing the potential for severe skin damage. Patients with certain circulatory issues may also have compromised skin integrity, making them more vulnerable to heat-related injury from direct application.