General body temperature refers to the axillary temperature, 35.5 ℃ does not belong to the normal body temperature, generally belongs to the body temperature is low. Normal body temperature axillary temperature in 36 ℃ ~ 37 ℃, the appearance of body temperature 35.5 ℃ may be related to measurement error, sweating, environmental factors, certain diseases and other reasons. It is recommended to consult a doctor in time to find out the cause after excluding non-self factors such as measurement error, profuse sweating and environmental factors. 1. Measurement error: If the thermometer is not clamped, or if the thermometer is not in the correct position, it can lead to low body temperature. 2. Heavy sweating: Heavy sweating after exercise or steaming without timely hydration may lead to low body temperature. 3. Environmental factors: Prolonged exposure to a low-temperature environment may cause hypothermia. 4. Certain diseases: such as hypothyroidism, shock and other conditions may also lead to hypothermia. Prolonged hypothermia or other discomforts should be treated promptly by a doctor.