Shortwave diathermy is an example of which heat transfer method?

• A. Conduction
• B. Convection
• C. Radiation
• D. Conversion

Answer: (C)

Shortwave diathermy heats tissues by radiating energy: the device emits high-frequency electromagnetic waves that travel through space and into the body, where the energy is absorbed and converted into heat inside the tissues. This fits radiation as the heat transfer mechanism because energy moves from the source to the body without needing direct contact or moving fluids. Conduction would require touch between objects, and convection relies on fluid movement to transfer heat, which isn’t how the energy initially arrives in this therapy. Inside the tissue, some of that absorbed energy is converted to heat, but the primary transfer is through electromagnetic radiation.