We call a cold a free for all. Their friends can still come over and play if they have had the cold already for a few days and they are sure it is nothing else. No fever, in infection, no diareaha and no lethargy. We didn't start out this way, but we decided that my son would NEVER be able to go to school, play with other kids and visit his cousins. Keep in mind that these kids still have to build up their immune system. Just be cautious as I am sure we all are by this point and try to let them have as much fun as possible. Good luck! LKT