Burn Percentage in Adults: Rule of Nines: In adults, the "rule of nines" is used to determine the body surface area that has been burned. Burn percentage is calculated using multiples of 9. The "rule of nines" helps determine treatment decisions.
Thermal Burns (Heat or Fire) Thermal burns are burns caused by heat, rather than chemicals or other causes. They can range from mild, like a sunburn, to severe. The burn severity is determined by the size of the area of the body with burns and how many layers of skin are involved.