I'm on a search and rescue team and 80% of the time my Lowa Mountains are perfect for the job. However this last week has been particularly cold; below -20 and the snow is still knee-waist deep. I've been finding my feet getting too cold when on extended jaunts that include time just standing around. Does anyone know of a really good boot make/model that will be just like my Lowa Mountains, only warmer? A decent 20mm of thinsulate would probably be fine in terms of extra lining - though was thinking I'd be better off with the slightly higher leg of the combat style boot. Anyone got experience of a decent set of boots that might work for me?