First-degree burns take between three and five days to heal, according to the University of New Mexico Hospitals. The burn heals when the injured skin peels off, revealing the healthy skin.
The Mayo Clinic notes that first-degree burns only affect the outer layer of skin; the burned skin appears red and swollen, and it can be painful. To reduce the pain and protect the skin, the patient can place a gauze bandage over the burn. Over-the-counter pain relievers, such as ibuprofen, naproxen and acetaminophen, can relieve pain associated with burns. Do not apply ice, butter and ointments, as they impair healing and increase the chances of infection. Seek medical attention if the area starts to ooze, swell or becomes severely painful.