Warts are caused by a virus that loves warm, moist environments, such as public swimming pools, showers, and gyms. They are highly contagious and can be easily picked up by wandering around barefoot. To lessen the risk of being infected with a wart you should always wear closed in footwear ,or at a minimum socks, when walking in public areas that are frequented by barefoot individuals. For areas like public showers I would recommend purchasing a pair of closed in “reef” shoes that are designed to be worn in aquatic situations where the feet need some form of protection.