I have heel blister issues with every boot. Some are better than others and after trying 6 different brands of boots I ended up with Lowa Tibets. That said, I will still get heel blisters if I wear for a week straight of hard hunting. So, I have learned to use a heel lock lacing technique, which further reduces my heel slip. Then,, always keep an extra pair of dry socks with you as damp socks lead to blisters. Last, leukotape for any hotspots and don't wait for the blister to form. The listed steps above worked for me and I hunted 10 days, with a few hot days mixed in without blister issues.