Depends on the type of hot. If it's a BTU hot, as in peppers - soak the inside of your mouth with milk. If it's a "heat" hot - munching on crushed ice is helpful, but, basically, your tongue will have to heal on it's own. It will be sore for a while.
Drink some milk. Just like milk helps relieve your mouth after eating hot or spicy food, milk also helps relieve burns. This is how it works. You have nerves throughout your body. When you get burned or eat something hot or spicy, your nerves go on red alert and tell your brain that it hurts. The result is a communication of nerves to your brain.