Answer:
The heat expands the lid of the jar, which facilitates its removal.
Explanation:
If you are having difficulty removing the lid from a jar, just use a little heat. You can pour a little hot water over the lid or dip the lid in the water for a while. When trying to open, it is important to use a cloth to increase the friction with the lid and also to prevent the heat from burning your hands. This trick is used to make the metal lid break with increasing temperature and thus eliminate the vacuum. You can do the same experiment using a hairdryer or a lighter to heat the lid, but be careful when handling these objects.
