1. First, open the game "Subway Parkour", click on the limited time activity, and click on the temperature value to sign in.
2. Secondly, 1 calorific value is given when you sign in one day, and you can get 5 calorific values when you complete a specific task.
3. Finally, if you have saved enough heat value of 1500, you can exchange it for Sister Lemon.