Can you get fungus on your head from wearing a hat all the time for too long that results in your hair falling out?
A fungus spreads from person to person. A hat worn by a person with a fungus could transmit the fungus as the hat is shared with another. Fungal infections love warm, moist environments and if you sweat from the hat that is carrying a fungus, you may get it. Depending on the fungus, hair loss could result. These are all longshots, but they are possibilities.