Adult body temperature of 35.5 degrees is below normal, which belongs to the condition of low body temperature. It may be caused by inaccurate measurement, underdressing and diseases, etc. The condition can be improved by general treatment and medical treatment. 1. Inaccurate measurement: If the armpits are not clamped, the measurement time is short or there is sweat in the armpits when measuring the body temperature, it may cause low body temperature, which should be re-measured by drying the sweat in the armpits, clamping the thermometer in the armpits, and controlling the measurement time at about 8-10 minutes before measurement. 2. Underdressed: low body temperature may be due to the measurement of the lower temperature or the patient is underdressed, resulting in a drop in body temperature, the patient should pay attention to the appropriate increase in clothing, appropriate warmth, away from the temperature of the environment is too low, so as not to affect the results of the measurement. 3. Disease: When the patient suffers from anemia, hypothyroidism, chronic cardiac insufficiency, liver failure and other diseases, may also cause hypothermia occurs, should be examined in detail, identify the cause of the disease according to the patient’s condition for targeted treatment. It is recommended that patients choose to measure their body temperature early in the morning, fasting, resting, awake state, measuring time is enough, while paying attention to monitoring the condition, regular review.