Infrared warmth: how does it work, and is it safe?
The short answer
Infrared warmth is the same form of heat as that of the sun or a wood fire: an invisible radiation that directly warms the body it reaches, without needing to heat the air in between. It has nothing to do with UV and does not tan. In a low-voltage battery accessory with overheating protection, it is safe as long as you follow a few simple habits, especially during prolonged use.
- Infrared ≠ ultraviolet: no tanning effect, non-ionising radiation.
- Warming the body rather than the room: that is the principle of targeted heating.
- For a long, quiet moment (reading, relaxing on the sofa, a short nap): the gentlest level and a layer of clothing between your skin and the product. Do not sleep through the night with a heated accessory.
1. The three ways heat is transferred
To understand the benefit of infrared, we need to go back to the three modes of heat transfer:
- Conduction: heat passes through direct contact, like a hand resting on a hot cup.
- Convection: air (or water) warms up and then circulates. This is how most radiators work: they heat the air in the room, which then warms you.
- Radiation: heat travels as waves and directly warms the surfaces it reaches. This is the case with the sun, an open fire… and infrared.
Convection has a drawback when you are alone and still in a large room: the whole volume of air must be heated for a few degrees to reach you. Radiation and conduction, on the other hand, target the body directly.
2. What exactly is infrared?
Infrared is a part of the light spectrum located just beyond visible red: our eyes cannot see it, but our skin feels it as warmth. Every warm object emits it — including our own body, as thermal cameras show.
It is important not to confuse it with ultraviolet, on the other side of the spectrum. UV is responsible for tanning and sunburn; infrared, by contrast, is non-ionising radiation: it carries heat, without the energy needed to alter cells as UV does.
3. How it works in a SUKHA object
Every SUKHA product contains a flexible graphene-based heating film, powered by a rechargeable battery at low voltage (5 V). It emits far infrared. Once switched on, it spreads an even warmth that warms you by contact and radiation, wherever the cushion is placed: the back, the tummy, the thighs.
- 3 levels: 40 °C, 45 °C or 50 °C, chosen with a simple press.
- Up to 9 h of warmth depending on the level (9 h at 40 °C, 4 h at 50 °C).
- Rechargeable battery included, USB-C charging with the charger you already own.
- Sheep's wool around the heating element: an insulator, it keeps the warmth against you and spreads the sensation.
4. Is it safe?
Yes, as long as you choose a product designed for it and use it correctly. Three things matter:
Low voltage
A battery accessory runs on extra-low voltage: no mains voltage flows through what you hold against you. And being cordless, there is no cable to trip over or get caught.
Overheating protection
It switches off or regulates the heating element if the temperature exceeds the set threshold. It is the first thing to check on any heated product, along with CE marking.
Contact time
This is the least known point. Moderate warmth is not harmful over a few minutes, but prolonged contact for hours with a warm surface can cause so-called “low-temperature” burns. Reference medical research has shown that several hours of contact at around 44 °C can be enough to damage the skin. Nothing to worry about with normal use, but it justifies the habits below.
Be especially careful if your sensitivity is reduced (diabetes, neuropathy, circulatory problems, medication that reduces alertness), during pregnancy, or for a young child: ask your doctor's advice before use.
5. 6 good habits
- Start at 40 °C and only increase if needed.
- For a long moment or a nap, stay on the gentlest level and keep a layer of clothing between your skin and the cushion.
- Keep 50 °C for short sessions, to warm up quickly.
- Change position from time to time rather than keeping the warmth in the same spot for hours.
- Charge on an open surface, not under a pillow or a duvet, with a compliant USB-C charger.
- Do not use a damaged product (torn cover, bent element, swollen battery): contact customer service.
Frequently asked questions
Does infrared warmth tan or age the skin?
No. Tanning and sunburn are caused by ultraviolet, on the other side of the light spectrum. Infrared carries heat, with no tanning effect.
Does an infrared heated cushion heat the room?
No, and that is the whole point: it warms the person in contact with it, not the volume of air in the room. It complements your heating, letting you stay comfortable with a lower room temperature.
Can you sleep with a heated accessory?
We do not recommend it for the night. A SUKHA is used while awake: sitting at your desk, settled on the sofa, to relax or for a short nap, on the gentlest level and with a layer of clothing between your skin and the product. Switch it off before falling asleep; people with reduced sensitivity to heat should ask their doctor's advice.
What is the difference between 40, 45 and 50 °C?
40 °C suits long sessions and offers maximum battery life (up to 9 h). 45 °C is the everyday comfort level. 50 °C lets you warm up quickly, ideally for shorter sessions.
Further reading
- Moritz A. R., Henriques F. C., “Studies of thermal injury”, American Journal of Pathology, 1947 — the reference study on the duration / temperature relationship of burns.
- SUKHA product instructions (safety and care guidelines).
Article written by the SUKHA team. It is for information only and does not replace the advice of a healthcare professional.