Characteristic is the appearance of bubbles with light contents on a superficially damaged skin layer. It is impossible to open them. Gently wipe the skin with alcohol and apply a sterile dressing. Do not rub or massage the skin when swelling and blisters appear, in such cases, warming can be carried out using a heat bath, the temperature of which should be gradually increased from 20 to 40 ± C for 20-30 minutes. Usually, after 10-12 days, the bubbles dry out and, if a small area was affected, after two to three weeks, recovery occurs.