In reply to Mike Brogden:
I think I have relatively narrow heels at least compared to almost square front bits of me feet! I've winter climbed lots for over 30 years and used lots of different boots, and I'm starting to wonder if it might not actually be a bit of an advantage. Buy your boots to fit the widest part of your feet - you'll have bags of space in front of your toes but that's good - you won't get cold feet as you'll have loads of wiggle room for toes. You also won't get bruised toes from front pointing or kicking steps because of that room. Someone else already said, Superfeet green insoles have a really deep heel cup that sort of pinches your heel and turns into a much chunkier pad that make walking much comfier. I used to get awful shin splints that just stopped once I got superfeet insoles. The ankle lacing can also really keep your heel in place.
So buy for width, not for length. For example 42s for me in approach shoes or trainers are really loose baggy fit - loads of space infront of my toes and around the heel. 41 generally better. But virtually all my winter boots are 42 and I can wear them all day, rarely worry about cold toes, don't get blisters etc. I've used Sportivas, Scarpas, Dolomite, AKU and probably some others I've forgotten down the year in winter boots. I've found most pretty good following the above rule. Good luck and don't forget comfy width, don't worry about space at the toes - you'll be the happy one with warm non bruised toes!
