The heat at the swelling needs to depend on where the swelling is, and it may say that there is swelling in the epidermis or in which part of the skin. Generally speaking, it may be a sign of inflammation, which is also known as infection, and infection can be characterized by redness, swelling, heat and pain. Red is a little red, swollen places reddish color; swelling is said to be swollen; heat is to feel the temperature of the surrounding skin is different, that is, some heat; pain is to press or feel a painful feeling. Redness, swelling, heat and pain are the clinical manifestations of inflammation or infection.