The band I'm in practices in a garage that's not insulated, so it can get to around 15-20 degrees some nights. After practice I throw a blanket over my head but I don't know how much that would help. Would cold weather hurt the sound of the tubes or decrease the life of them? I warm up the head about 15 to 20 minutes before playing on it. Oh, and it's a 3 channel Dual Rectifier if that matters. I've got another head I could leave there for practice but where I live it's hard to get a lot of shows so I'd hate to only use my Mesa for shows since it's sounds so awesome. Any help would be appreciated. Thanks.