The document discusses the physiologic effects and application methods of heat and cold therapy in nursing. It states that heat therapy causes vasodilation and increases blood flow and cellular metabolism, while cold therapy causes vasoconstriction and decreases blood flow and metabolism. It provides guidelines for safe heat and cold application, such as checking the area every 15-20 minutes and limiting application to 30 minutes to avoid rebound effects. A variety of methods are described for dry and moist heat application and dry cold application using items like hot water bottles, cold packs, and baths.