Be careful with causing excessive heat stress to small parts, especially springs. If a part is not designed to be heated to high-ish temps (like a hair dryer over a period of time) you could weaken something and not know it.
Another cleaning product that can be used once in a while is Simple Green. Yes, that stuff thats under the sink. Its a non-toxic degreaser. I don't use it much but it worked great on cosmoline. And since its non-toxic it safer than some of the other stuff we use. If you aren't sure if it will take off whatever gunk you're trying, give it a shot.
Some lubes work fine in extreme cold. I've had good luck with MP-10 (I think it is). I tested it a year or two back by leaving my vehicle gun secured in my rig overnight when it was due to be sub-zero. Before starting the rig I moved it to the back and insulated it with a blanket so it wouldn't warm up. Drove the half hour to the range and it emptied just fine. After that I ceased worrying about it. I've heard that some dry lubes work fine but I'd rather get the dry grafite spray for locks as its designed for tight clearences. Stuff works fine in my door locks and we had a cold spell not to long ago up here. Don't recall the brand and the can is in the garage. I just remember that the can is small and blue (I know, not much help).
Don't forget to clean your magazines as well. In order for your semi-auto to function well the mags have got to be up to snuff. Most mags are fairly easy to disassemble, just be careful where you point it as you are removing the base. Yes things have flown across the room before.
Steelheart