Which type of radiant energy is primarily used to stimulate local circulation by heating tissues?

• A. Infrared radiation
• B. Ultraviolet radiation
• C. Minimal erythema
• D. Second-degree erythema

Answer: (A)

Infrared energy is used to heat tissues and boost local circulation. Its heat penetrates beneath the surface, warming deeper tissues and triggering vasodilation, which increases blood flow and enhances healing-related processes in the treated area. Ultraviolet energy, on the other hand, is energetic enough to cause photochemical skin effects and damage rather than providing controlled heating to stimulate circulation. The terms minimal erythema and second-degree erythema describe skin reactions to UV exposure, not a type of radiant energy. So infrared radiation best fits the idea of heating tissue to stimulate local circulation.