Redness of the skin after sun exposure is due to a slight inflammation of the skin, which is a symptom of sunburn. The first thing to do is to apply cold compresses in a timely manner, and if there is no relief, medication can be given. 1. Cold compresses: you can use refrigerated saline or mineral water for 10-20 minutes each time, which can lower the skin temperature and avoid further damage to the skin. 2. Drug treatment: generally can be used externally with glycerine lotion and (or) glucocorticoids (mometasone furoate cream), in severe cases, 3% boric acid solution can be used as a wet compress. Those with systemic symptoms can take oral antihistamines (loratadine), vitamin C, non-steroidal anti-inflammatory drugs (ibuprofen), and in severe cases, glucocorticosteroids such as dexamethasone tablets can be applied systematically. Pay attention to sun protection in daily life, such as applying sunscreen and wearing sun-protective clothing, to avoid skin redness after sun exposure. When the above situation occurs, it is recommended to go to the hospital in time to receive standardized diagnosis and treatment, and the medication should be used according to the doctor’s prescription.