According to the Official Elf on the Shelf website ... will give him or her the strength to make it back to the North Pole, so Elf doctors can tend to them. The next day, your Elf will return ...
Per official Elf on the Shelf lore ... you can have their elf spend a day away at the North Pole. Write a brief letter from your elf to explain that because they were touched, they have to ...