You should never apply what to a burn as it causes further tissue damage?

Applying ice to a burn is harmful because it can cause further tissue damage. Burns already compromise the skin's integrity and applying ice can constrict blood vessels, reducing blood flow to the area and potentially causing frostbite in addition to the existing burn injury. It also can exacerbate the injury and lead to more pain and prolonged healing time. In contrast, practices like running cool water over a burn can help soothe the pain without the risk of further tissue injury, making it critical to avoid the application of ice directly on a burn.