When you get a burnt tongue you should immediately rinse the tongue with some cool water and also drink some cool water which can soothe the burnt tongue.
After that try sucking on some ice cubes and the ice cubes will also help relieve the burning sensation of the tongue.
You can also suck on a popsicle but avoid any hot liquids until the burnt tongue heals as the hot liquids could irritate the burnt tongue.
After a few days to a week of sucking on the ice cubes or popsicle and drinking some cool water the burnt tongue should heal.
Gargling with some salt water or apple cider vinegar can also help soothe and heal the burnt tongue.