What did Babe Ruth wear under his cap to keep cool?

Babe introduced to his teammates an unusual technique for keeping cool: He pried the leaves off a head of cabbage and spread them over the ice in a cooler. When they were sufficiently chilled, a leaf under the cap would supply much-needed relief for a few innings before needing to be replaced. A large man with an extra-large noggin, the Babe was said to require two leaves for the method to be fully effective.