These boots will come up half way up your calf.  The comfort zone is -50F to65F. There are 6 layers to help keep your feet warm

Extreme Conditions Winter Boot
Layers of warmth in a slim profile hug your feet and keep you warm and comfortable all day.
DS1 molded outsole – outer and inner grip
6 layers of protection plus EVA cold-blocking midsole = 7 layers
5.5 mm bootie 2.5 mm DENSOPRENE XD foam (extreme density) for extra protection 2 mm airmesh 2 mm warm fleece lining = 11 mm of insulating warmth and protection!
Removable molded EVA sockliner
Double achilles heel and instep reinforcement for comfort and protection
Nylon shank