The skin around a cut becomes red and warm as part of the

A wound infection occurs when germs, such as bacteria, grow within the damaged skin of a wound. Symptoms can include increasing pain, swelling, and redness. More severe infections may cause nausea, chills, or fever.

A person may be able to treat minor wound infections at home. However, people with more severe or persistent wound infections should seek medical attention.

in the explanation box

Explanation:

body's immune system trying to protect the wound from infection. The wound becomes red because blood vessels are opening so blood can bring oxygen and nutrients to the cut area, oxygen is needed for healing.