A burn is tissue damage, typically affecting the epidermis and dermis, caused by heat, chemicals, electricity, or radiation. While the goal is to stop the burning process and cool the injury, applying ice is a mistake that can worsen the damage. This seemingly logical first-aid step is counterproductive, potentially leading to more severe injury than the initial heat exposure. Understanding the underlying biology explains why cool running water is the only safe and effective treatment.
The Physiological Danger of Applying Ice
Applying ice directly to a burn initiates a protective biological response that ultimately harms the already compromised tissue. The extreme cold causes immediate and intense vasoconstriction, which is the narrowing of local blood vessels. This reflex severely restricts blood flow to the injured site, reducing the delivery of oxygen and nutrients to the damaged cells.
The lack of circulation traps residual heat within the deeper tissue layers, preventing the body from dissipating it effectively. Furthermore, the lack of blood flow, known as ischemia, can lead to secondary tissue damage and cell death, deepening the burn injury. Direct application of ice also carries the risk of causing a cold injury, like frostnip or frostbite, compounding the initial thermal burn.
How Running Water Differs from Ice
Cool running water is the widely recommended first-aid measure because it achieves the necessary heat extraction without triggering harmful vasoconstriction. Water continuously draws heat away from the burn site through convection, effectively cooling the tissue and stopping the burning process. This continuous removal of heat minimizes the amount of tissue damage and prevents the burn from progressing deeper into the skin layers.
The ideal temperature for this cooling process is cool tap water, typically between 15°C and 25°C, applied for at least 20 minutes immediately after the injury. This temperature range is low enough to relieve pain and reduce swelling but avoids excessive blood vessel constriction. Running water also reduces the inflammatory response, which helps limit long-term scarring and promotes better recovery.
When a Burn Requires Professional Medical Attention
Minor first-degree burns can often be managed at home with proper cooling. However, several factors indicate a burn injury requires immediate professional assessment.
Any burn presenting with blisters (second-degree) or a charred, leathery, or white appearance (third-degree) necessitates medical care. A third-degree burn may not be painful because the nerve endings have been destroyed.
Seek medical help if the burn is larger than three inches in diameter or covers sensitive areas, such as the face, hands, feet, genitals, or a major joint. Burns caused by chemicals or electricity require immediate attention due to potential internal damage. Burns in vulnerable populations, including infants, the elderly, or those with pre-existing medical conditions, should always be evaluated.