What change occurs to the skin when heat is applied?

When heat is applied to the skin, the correct change that occurs is that the skin becomes red and warm. This response is primarily due to the dilation of blood vessels, a process known as vasodilation. When heat is introduced, the body responds by increasing blood flow to the area, which results in a warm sensation. The increased blood flow also leads to the characteristic reddening of the skin, as more oxygenated blood reaches the surface. This response is important as it aids in regulation and can help the body deal with tissue repair or inflammation.

Although other options suggest different skin reactions, they do not reflect the typical physiological response to heat application. For instance, pallor and coolness indicate reduced blood flow, while a bluish color suggests decreased oxygenation. Blistering occurs as a result of burns or severe tissue damage, which is not the case with normal heat application. Understanding these responses is crucial for effective wound care and treatment.