Itchy red bumps on the body in hot weather are usually related to papular urticaria, eczema and other causes, which can usually be treated with topical as well as oral medications to improve the symptoms. 1. Pemphigus urticaria: There are more insects in summer, and insect bites may cause red bumps, itching and other allergic reactions, called pemphigus urticaria. Can be used externally under the guidance of a doctor, mometasone furoate gel, Dinaid ointment, glycerine lotion and other drugs, to play the effect of anti-inflammatory and anti-itching. When the itching is significant, oral antihistamine can be taken, such as cetirizine. 2. Eczema: Some people are relatively sensitive to obvious temperature and humidity changes, and high temperature and humidity in hot weather may cause eczema flare-ups, small red bumps, itching and other symptoms. You can follow the doctor’s instructions to use topical glucocorticoid drugs such as compound flumethasone ointment, or calcium-modulated phosphatase inhibitors such as tacrolimus ointment and other drugs to improve the local itching, and to promote the receding of the rash. However, this symptom alone is not enough to diagnose the disease, and may be caused by other factors. It is recommended that the patient consult a doctor in time to clarify the cause and give targeted treatment, do not blindly self-medication.