Well I've had heart troubles since my early 40's and between that and the required meds feet are a problem. I got some cabela's ultimate -140 1200 grm thinsulate with pac liners besides and they have been a goddsend as I am limited to stand hunting anymore. They also made ice fishing viable for me again. If someone is in extremes I would highly recommend them. Prior to all that 600 grms always worked for me, with appropriate socks, etc.
Scott
