It doesn't need heating. Generally, it tastes best without refrigeration and heating. If you buy it from the supermarket refrigerator, it is suggested that it will taste better after it returns to normal temperature, and you can also dip it in vinegar according to your personal hobbies.

Extended information

Sushi has been recorded in the heian period Code "Yanxi Style" completed in 927 AD. Sushi at that time refers to a way to preserve fish. Rub salt on the fish, press it with heavy objects and let it ferment naturally. When it is sour, it can be eaten by wrapping it with japonica rice.

Reference: Baidu Encyclopedia-Sushi.