i don't know, i use to be afraid of heights too, but i was so focused on the climbing that i only got scared on the way down, also it was good motivation for not falling so i was able to climb harder stuff faster unfortunatly now i like hanging around way off the ground and my climbing level has almost pleatued
added benifit though is now that i work construction i can just about run around on top of the secound story walls that are 5 1/2 in thick and 20 or so ft of the ground without to much problem.