Which statement about heating is true?

• A. It raises tissue temperatures
• B. It lowers tissue temperatures
• C. It increases tissue oxygenation
• D. It decreases hematocrit

Answer: (A)

Heating primarily raises tissue temperature. When heat is applied, energy moves into the tissues, increasing their temperature. That temperature rise triggers physiological responses such as vasodilation and increased local blood flow, higher metabolic activity in the area, and faster nerve conduction, which is why heat is used to ease stiffness and pain. The other statements don’t describe the immediate, universal effect of heating: it doesn’t lower tissue temperatures, it doesn’t decrease hematocrit, and while improved blood flow can influence oxygen delivery, the defining, direct effect of heating is the temperature rise.