Most burns are minor injuries that occur at home or work. It is common to get a minor burn from hot water, a curling iron, or touching a hot stove. Home treatment is usually all that is needed for healing and to prevent other problems, such as infection.
There are many types of burns.

Heat burns (thermal burns) are caused by fire, steam, hot objects, or hot liquids. Scald burns with hot liquid are the most common burns to children and older adults.

Electrical burns are caused by contact with electrical sources or by lightning.

Chemical burns are caused by contact with household or industrial chemicals in a liquid, solid, or gas form. Natural foods such as chili peppers, which contain a substance irritating to the skin, can cause a burning sensation.

Radiation burns are caused by the sun, tanning booths, sunlamps, X-rays, or radiation therapy for cancer treatment.

Friction burns are caused by contact with any hard surface such as roads ("road rash"), carpets, or gym floor surfaces. They are usually both a scrape (abrasion) and a heat burn. Friction burns to the skin are seen in athletes who fall on floors, courts, or tracks.

 Motorcycle or bicycle riders who have road accidents while not wearing protective clothing might get friction burns. For information on treatment for friction burns, see the topic Scrapes.

Breathing in hot air or gases can cause injury your lungs (inhalation injuries). Breathing in toxic gases, such as carbon monoxide, can cause poisoning.

Burns injure the skin layers and can also injure other parts of the body, such as muscles, nerves, lungs, and eyes. Burns are defined as first-, second-, third-, or fourth-degree, depending on how many layers of skin and tissue are burned. The deeper the burn and the larger the burned area, the more serious the burn is.

First-degree burns are burns of the first layer of skin. See an illustration of a first-degree burn.

There are two types of second-degree burns:
Superficial partial-thickness burns injure the first and second layers of skin. See an illustration of this type of second-degree burn.
Deep partial-thickness burns injure deeper skin layers. See an illustration of this type of deep second-degree burn.

Third-degree burns (full-thickness burns) injure all the skin layers and tissue under the skin. See an illustration of a third-degree burn.These burns always require medical treatment.

Fourth-degree burns extend through the skin to injure muscle, ligaments, tendons, nerves, blood vessels, and bones. These burns always require medical treatment.

The seriousness of a burn is determined by several factors, including:
The depth, size, cause, affected body area, age, and health of the burn victim.
Any other injuries that occurred, and the need for follow-up care.
Burns affect people of all ages, though some are at higher risk than others.
About 20% of burns occur in children younger than age 5, and most of these are scald burns from hot liquids.
About 60% of burns occur in the 18- to 64-year-old age group.
About 10% of burns occur in older adults, mostly scald burns from hot liquids.
Men are twice as likely to have burn injuries as women.

Burns in children

Babies and young children may have a more severe reaction from a burn than an adult. A burn in an adult may cause a minor loss of fluids from the body, but in a baby or young child, the same size and depth of a burn may cause a severe fluid loss.

A child's age determines how safe his or her environment needs to be, as well as how much the child needs to be supervised. At each stage of a child's life, look for burn hazards and use appropriate safety measures. Since most burns happen in the home, simple safety measures might prevent accidents and decrease the chance of anyone getting burned. See the Prevention section of this topic.

Most burns are accidental. When a child or vulnerable adult is burned, it is important to find out how the burn happened. If the reported cause of the burn does not match how the burn looks, abuse must be considered. Self-inflicted burns will require treatment as well as an evaluation of the person's emotional health.

Infection is a concern with all burns. Watch for signs of infection during the healing process. Home treatment for a minor burn will reduce the risk of infection. Deep burns with open blisters are more likely to become infected and need medical treatment.