Its a scary condition especially when you realize its not just a thing that happens in NY in February. Our bodies are amazing environmental engines but dangerous extremes are less extreme than we might guess. Think about it, 98.6 your body is perfect, a few degrees higher and your nearly dead, a few degrees colder, same thing! The balance can be upset much more easily than we would imagine. Although Ive had frostbite and chilblain, Ive never reached a point of hypothermia even living in the North East my entire life and training in Fort Drum in the middle of the winter every year.
US Army Public Health Command lists these symptoms----
1-- Vigorous shivering is typically present. Shivering may decrease or cease as core temperature continues to fall.
2-- Onset of hypothermia is typically associated with the so-called “umbles”, the grumbles, mumbles, stumbles and fumbles that increase as cold affects muscle and nerve function.
3-- Symptoms of hypothermia consist of confusion, sleepiness, slurred speech, shallow breathing, weak pulse, low blood pressure, change in behavior and/or poor control over body movements/slow reactions.
A healthy body is not as prone to Hypothermia but not exempt either. Our engines need fuel and hydration to create heat, when they run low, so does the heat. Nearing Hypothermia can be halted by early detection and reversed by exercise, nourishment and hydration. Once the signs begin, your on borrowed time unless you can get your motor running and fast!
Fight the cold by being prepared for it first, like others have said layers and materials that wick away sweat and dont absorb it are key to sustained exposure. More folks get hot and cold weather injuries when they didnt expect they could happen. Elderly and children with dementia or developmental disabilities that get disoriented and lost, Car breaks down, rapid weather changes while out for a short bike or hike or injuries sustained prior to hypothermia that immobilize you away from assistance are far more common than a prepared hunter getting lost and becoming Hypothermic.
My wife and I keep a good blanket in our vehicles year round, I used mine last winter when my thermostat stuck closed on my PU last winter 4 miles down the road from home, it was 20 below and 7:00 in the morning! I wasnt in danger cause I had a cellphone and could have called for help if I needed it or just flagged down a car. The cheap stubborn German in me made me wrap up in the blanket, hold on and try starting it every 10 or 15 minutes and wait for the heat of the engine block to pop the thermostat open. About half an hour later, I heard a little ping, pop and trickle as the fluid started circulating through the system. 2 minutes later there was heat! Then my blood started circulating and all the sudden, life was good. If I hadnt had the blanket, gloves and a little patience, I would have been regretting that "should have been a 10 minute drive" in big ways.
Boy Scouts say "Be Prepared" for a reason.