I hike a LOT - almost every weekend with the Appalachian Mountain Club. I tried many many boots, and ended up with a pair from REI - Lowa ($180) and they are worth every penny. I hike in both hot and cold conditions with them. When trying them on, be sure to use their wedge that simulates hiking down hill. It is very important to make sure your toes do not hit the front when hiking down hill or you will end up with blisters! If you have an REI near you - go there, they spent 2+ hours with me making sure I got the right fit. To try out boots, I would take them to a mall (indoors) and walk around for a few hours.
Trish