Early identification of severe cases of HFMD has the following points: 1. persistent hyperthermia Body temperature (axillary temperature) is greater than 39℃, and conventional antipyretic effect is not effective. 2. Neurological manifestations Mental depression, vomiting, easily startled, shaking limbs, weakness, unsteadiness in standing or sitting, etc., and in rare cases, hyperphagia. 3. Respiratory abnormalities Respiration may increase, decrease or become irregularly rhythmic. If the respiratory rate exceeds 30-40 breaths/min (according to age) in a quiet state, neurogenic pulmonary edema should be alerted. 4.Circulatory dysfunction Cold sweating, cold extremities, skin pattern, increased heart rate (>140-150 beats/min, according to age), increased blood pressure, and prolonged capillary refill time (>2 seconds). 5.Elevated peripheral blood WBC count Peripheral blood WBC exceeds 15×109/L, except for other infectious factors. 6. Elevated blood glucose Appears as stress hyperglycemia with blood glucose >8.3 mmol/L. Early cerebrospinal fluid examination and MRI should be performed in cases with suspected neurological involvement. the key to screening severe cases of EV71 infection is to closely observe the mental status of the child, the presence of limb tremors, easy startle, skin temperature, as well as respiration, heart rate and blood pressure, and to record them in a timely manner.