Hot application involves applying heat to the body in either a dry or moist form at a temperature warmer than skin. Dry heat methods include poultices, diathermy, and aquathermia pads while moist heat includes whirlpool baths. Hot applications are used to decrease pain, promote circulation and healing, relax muscles, and relieve conditions like muscle spasms, arthritis, gout, and fatigue. Precautions include risks of burns, drying skin, impaired vascular supply, hypotension, and hyperthermia.