In freezing and sub freezing tempatures, if the fuel is allowed to cool too much, it will gel up and colg the fuel lines. (especialy if you have a filter) If it's not tooooo cold and you don't let the fuel sit out in the cold while it in the bottle you shouldn't have any problems. In really cold temps the fuel in the tank may get cold enough to gel but if you keep the engine running it will probably get burned before this has a chance to occur. If it does well you could always try insulating the tank too.