when i had hypothermia, i was OK as long as we were retreating (got caught in an unexpected hail/sleet storm trying to get over a pass - poor decision making on our part). once we stopped and started setting up camp, I began to mentally deteriorate.

if you are ever hiking with someone who you believe is beginning to get hypothermic, DO NOT BELIEVE ANYTHING THEY SAY. They may, like i did, insist that once they have changed into dry clothes they are fine. I wasn't. I was still cold, disoriented, and in danger. You basically have to treat them like a baby - supervise everything they do. i got into dry clothes, but still had on my wet underwear - my poor husband was busy making me hot food and didn't supervise me. He saved my life, but I sure didn't help!

Again, someone who is hypothermic, even mildly, must be treated like and taken care of like a small child. They will be embarassed about it, may fight you, but unfortunately you have to take over and be Mom or Dad until they are out of danger.