It's getting cold now. I change water with the tortoise every day, but it feels too cold. Will turtles freeze to death?

Turtles are cold-blooded animals and won't freeze to death. It's a little difficult for such a small turtle to spend the winter, but I suggest it's better to spend the winter. Whether it will die in hibernation or not, it must first obey its natural laws, otherwise even if it is alive without hibernation, its resistance will not be as good as before. It's best not to keep the turtle's container transparent, otherwise the turtle doesn't know, and it may get hurt if it bumps there all the time. Hibernation can be done in shallow water, and I personally think it can also be done in wet towels. Change the water when it is dirty, and keep the surrounding environment clean, otherwise it is easy to get infected with germs.