What happens to all the shirts and hats of the losing team in the super bowl?

They send them to some of the 3rd world countries for extra clothes, like last year they sent the New England Patriots shirts and hats to a girls soccer team and their village

Well, in the case of the Super bBowl this year the losing teams t-shirts (and losing playoff teams) were donated to World Vision who works to improve the lives of children in over 100 countries. World Vision has been giving away the losing team/misprinted products since 1994.

This years misprinted t-shirts will be donated in Nicaragua, Romania, and several other countries. The value of these t-shirts being donated is millions of dollars. These t-shirts will be the first time many folks have ever owned new clothes. In many of the countries food is the number one priority and warm clothes are a luxury so these donations really make a difference and spread the NFL brand to remote parts of the world.