What is the difference between shortwave and longwave infrared?

The difference between short-, mid- and long-wave infrared lies in the amount of energy they contain and how the heat is experienced and absorbed by the body.

Short-wave infrared contains a high level of energy and can heat the skin surface quickly and intensely. As a result, the heat often feels very strong and sessions are typically short. Due to the high energy density, exposure should be limited to a maximum of 10 minutes. Longer exposure may increase the risk of cellular stress, accelerated skin ageing and potential damage at a cellular level. There is also a risk of superficial overheating, and this type of infrared is generally not recommended for people with implants or prostheses.

Mid-wave infrared also has a relatively high heat intensity and is often used as a heating source, for example in patio heaters. At close range, skin temperature can rise quickly. For this reason, it is less suitable for sauna use, as the heat can become uncomfortably intense after 5 to 10 minutes, limiting session duration.

Long-wave infrared has a lower surface heat intensity and therefore feels softer and more comfortable. Wavelengths around 6000 nanometres allow for a gradual warming process, enabling heat to be distributed more deeply throughout the body via circulation. This allows the core body temperature to rise without overheating the skin.

Health Mate infrared saunas use only long-wave infrared radiation, as it is best suited for comfortable, longer sessions and therapeutic applications such as pain relief, recovery and immune support.

Differences in user experience

	short-wave infrared	mid-wave infrared	long-wave infrared
heat sensation	very intense, superficial	intense, quickly feels hot	gentle and comfortable
heat effect	mainly skin surface	skin and superficial tissues	gradual warming via circulation
session duration	short	short	longer sessions possible
core temperature increase	limited	limited	±0.5–1°C possible