Shivering and weakness are considered possible febrile illnesses. Febrile illness is preceded by chills, shivering, weakness, aching limbs and joints, headache, nausea or vomiting. This is usually accompanied by a cough, runny nose, and coughing up phlegm, usually due to an upper respiratory tract infection. Upper respiratory tract infections are more commonly associated with viral infections, where toxins are absorbed into the bloodstream, leading to an elevated body temperature. When high, it can reach up to 39℃-40℃. Therefore, it is recommended to immediately perform routine blood tests, blood bacterial culture and drug sensitivity test, calcitoninogen measurement, temperature measurement to clarify whether there is fever, give symptomatic treatment, drink more water. Immediately go to the hospital for a comprehensive examination to avoid delay.