Infrared radiation is a form of electromagnetic radiation that has longer wavelengths than visible light. While prolonged exposure to high levels of infrared radiation can be harmful to the skin and eyes, it is not typically considered harmful to the hair.
In fact, some hair styling tools such as infrared hair dryers and flat irons use infrared radiation to help dry and style hair more efficiently. Infrared radiation can help to penetrate the hair shaft and dry the hair from the inside out, which can help to reduce the amount of time that hair is exposed to heat and reduce the risk of damage.
However, as with any type of heat styling, it is important to use infrared hair tools properly to avoid damaging the hair. It is recommended to use a heat protectant product before using any heat styling tools and to avoid using high heat settings for prolonged periods of time. Additionally, it is important to maintain healthy hair habits, such as regular conditioning and minimizing the use of heat styling tools, to help keep hair healthy and strong.