Significant discrepancy between skin temperature and body temperature

The watch measures the skin temperature on the surface of the wrist. At a room temperature of about 25°C, the wrist temperature of the human body is about 32°C to 34°C. The wrist temperature may vary depending on the individual and environment.

Skin temperature measurements fluctuate

Skin temperature is greatly affected by environmental factors, such as whether the sleeves cover the wrist, whether there is a source of cold/heat such as an air conditioner or heating device, and whether there is significant airflow.

The skin temperature fluctuates within the first 10 minutes of putting on your watch/band due to thermal equilibrium between your watch/band and your wrist. Try measuring the temperature 10 to 30 minutes after putting on your watch/band.

The measurement is inaccurate when I take off my watch/band and another person puts it on to start a measurement

Wrist temperature and physiological metrics vary by individual. When another person puts the watch/band on, it will take a while for the watch/band and the wrist of the new person to reach thermal equilibrium. The watch/band will need to collect physiological metrics of the person for calculation and it will take at least 10 to 30 minutes before the watch/band can accurately measure the temperature.