Hi all, OP here, I actually got kinda lucky since my bf, who was going to the gym later, brought the flip flops that he wears in the school shower and he gave me those. So I didn't have to go the whole day totally barefoot but it was still kinda cold. On the bright side, this experience forced me to get over my dislike of wearing sandals/flip flops in public so that's good. Anyway, thanks for the suggestions and funny comments!