Abstract: Objective Statistical analysis of common features of cardiac arrest in patients with fever, to study the early identification and prevention of cardiac arrest in patients with fever. Methods Retrospective review of 32 cases of fever was the first symptom from 2008 January to 2018 October in Zhejiang Province People's Hospital through the electronic medical record database. Those included the data of before the fever, arrived at the hospital, 1 hour before sudden death, the change of Na⁺, K⁺, PH, Lac, breathing frequency, heart rate, blood pressure, SPO₂, consciousness, treatment, antipyretic drugs, volume of liquid, ever used diuretics. Through the analysis of the above data, the common characteristics of patients with fever before sudden death in hospital were summarized. Results The change of conscious were happened in all patients, 81.25% of patients have used different types of antipyretic drugs, only one patient Intravenous fluid supplementation 1 000 mL after antipyretic drug, seven peoples ever used diuretics, 21.88%. The heart rate of 1 hour before sudden death increased significantly compared to before the fever and arrived at the hospital, and sinus arrhythmia, increased heart rate was not proportional to increased body temperature. Breathing frequency increased significantly. No significant difference between blood pressure and SPO₂. The PH,BE, Lac of 1 hour before sudden death increased significantly compared to before the fever and arrived at the hospital. No significant difference between Na⁺ and K⁺. The incidence of "Moore's death"(A triangle of Na⁺, K⁺ and PH) was significantly increased. Conclusion Sudden death in hospital of Fever patient has very high risk of doctor-patient disputes, early detection and prevention through the changes in the patient's vital signs and test results. These results may help us reduce medical interventions that may increase the risk of sudden death and deduce the incidence of sudden hospital deaths in such patients.