Fever is a reaction of the body’s immunity to self-protection. The question of whether to apply hot or cold compresses to a fever of 38°C depends on which cause the fever is caused by. If the fever is caused by wind-cold, you can apply hot compresses. The symptoms of fever caused by wind-cold will be more serious, and the fever is relatively light, usually headache, aching limbs, nasal congestion is serious, there will be clear nasal discharge, the throat will feel itchy, there will be white phlegm coughing out, you can use Jing Fang Defeat Poison San. If the fever is caused by wind-heat cold, you can apply cold compresses. The symptoms of fever caused by wind-heat are generally a general feeling of fever, head is swollen and painful, cough, yellow phlegm, yellow nasal discharge, feeling thirsty and can use Yin Qiao San to assist in treatment.