Busch/Busch Light Navy Coolie featuring Busch on one side with Busch Light on other with mountain logo in navy and white. Coolies keep your beer cold by preventing condensation. Condensation allows for the heat and humidity from the outside to have a lasting effect on the cold beer inside by forcing the cold to seep out the sides. In other words view condensation as the tears of your beer. Don't let your beer cry, coolies save beer, buy a coolie and save your beer before it's too late!