Hair dryere dont get quite HOT enough... but if you BLOCK the air going INTO the hairdryer with your hand... then the air blowing out gets lots hotter. The problem you may run into is there is an OVERHEAT fuse link inside all newer hair dryers. If you overheat the dryer, it will trip this fuse. This may ruin your hair dryer. If you only block a LITTLE of the air going in... maybe you will not trip the fuse-link. You can also shrink the tubes by holding your soldering iron very close but not touching it. Only works if no breeze is blowing (working outside breeze or deskfan blowing). Hold the iron UNDERNEATH because heat RISES.