A burn is tissue damage caused by energy transfer, most commonly from heat, but also from chemicals, electricity, or radiation. When skin and underlying tissues absorb this energy, cells are damaged or destroyed. The immediate and universally recommended first aid for a thermal burn is the application of cool running water. This rapid intervention actively limits the extent of the injury and improves the long-term outcome.
How Cold Water Interrupts the Heat Transfer
Even after the initial source is removed, the heat absorbed by the tissue continues to spread to deeper layers, known as residual heat. Applying cool running water immediately interrupts this destructive process. The water acts as an efficient heat sink, rapidly drawing thermal energy away from the burn site through convection and conduction. This rapid thermal exchange quickly lowers the temperature of the affected tissue, halting the progression of damage into deeper layers of skin. A secondary benefit of immediate cooling is the direct reduction of pain, as the lower temperature temporarily numbs the exposed nerve endings.
Minimizing the Inflammatory Response
The secondary phase of a burn injury involves a biological response where damaged cells release chemical signals called inflammatory mediators. These substances increase the permeability of local blood vessels, allowing fluid to leak into the surrounding tissue, leading to swelling (edema). Edema can compromise blood supply and tissue viability. Cooling the burn helps stabilize blood vessels and reduces the release of these chemicals. The lower temperature induces vasoconstriction, limiting fluid leakage and helping preserve tissue in the “zone of stasis.”
Guidelines for Applying Cold Water Treatment
Temperature and Duration
The effectiveness of water depends on its correct application, including temperature and duration. The recommended standard is to use cool or lukewarm running water, ideally between 8°C and 25°C, for a continuous period. The duration of cooling should be for at least 10 to 20 minutes, which is necessary to remove residual heat from the deeper tissues.
Important Precautions
It is important to avoid using ice, iced water, or freezing water. Intense cold can cause further damage to the compromised tissue and may lead to frostbite or profound vasoconstriction. Care must also be taken to keep the rest of the person warm, especially when cooling large burn areas, to prevent the risk of hypothermia.
When to Seek Medical Attention
Medical attention is required for any burn that is large (bigger than the size of the person’s hand) or deep (appearing white, charred, or leathery). Burns on sensitive areas, such as the face, hands, feet, or joints, also warrant professional medical assessment. After cooling, the burn should be covered loosely with a non-stick material, like clean plastic wrap, to prevent infection and reduce pain.