Exercise is generally not allowed when you have a fever because it can have a serious effect on a cold and fever. Cold is an acute upper respiratory tract infection that can cause fever, but also a variety of clinical symptoms such as nasal congestion, runny nose, and cough and sore throat. Therefore, patients with colds can lose a lot of body fluids and energy, and exercise can lead to energy consumption and water loss, so exercise for patients with colds and fevers may lead to persistent fever and aggravate the symptoms of cough and sore throat. Therefore, patients with fever should rest, drink more warm water, replenish body fluids, and give rehydration if the fever does not go away.