Heat gun or blow dryer?

I've tried several different hair dryers over the years, and most heat shrink tubes just shrug them off. You need to remember that hair-dryer manufacturers probably have the ladies' hair in mind and don't want to melt them, so they may suck 1200 watts out of the wall, but the airspeed is high enough to not burn their hair. On the other hand, the heat guns usually pull more electrons out of the wall, but at a speed that Does make high temps possible. But I wouldn't recommend your GF use one as a hair dryer, unless maybe she's 12 feet tall, and has hair like king-kong!