1. Pour water into the cup and tighten the lid.

2. Shake it back and forth for more than ten times, let it stand for 1 min, and then unscrew the lid.

3. The original boiling water in the cup is quickly cooled into drinkable warm water, which can be kept warm for about 3 hours.

4. When the water temperature gradually drops below 55 degrees, the cup wall releases heat slowly, thus achieving the function of heat preservation and keeping the temperature at 55 degrees all the time.