Maybe someone can speak to "realistic" treatment in a wilderness environment with no hope of extraction for very long time, if ever.
Mountains of information on treatment in hospital, very little, if any about dealing with it, if little or nothing is available.
Sourdough, the information you are looking for is indeed out there, just possibly, not in the format that you were looking for. Most "Training" out there from SERE, to Wilderness Survival Training mainly focuses on stabilizing and getting the patient to a hospital. As you mentioned, this can't always be accomplished.
I am going to copy and paste the rest from a portion of an article I wrote for treating hypothermia in the field..
When a person is suffering from hypothermia what to do:
If the person for example fell into a crack in the ice in a lake, hypothermia can occur 25 times faster, and can set within minutes if not less.
In this situation, once the person is out of the water, remove all articles of clothing, and quickly dry the person as moisture pulls heat away from the body 25 times faster than when the patient is dry.
[Now a person's instinct is to undress and lie down next to the hypothermic individual to warm them up. This would be a mistake. For starters, especially if it is just the two of you, lying next to your friend/patient, you would lose a lot of your own warmth, risking hypothermia for yourself as well.]
Next immediately put on the patien,t dry cloths, and socks and then place the person in a solar blanket or sleeping bag.
The best thing to do to manage the person's body temperature is to raise their core body temperature and blood. For the core temperature, this can be done by placing 2 hand warmers (hot rocks) on their chest area (place hand warmers in socks to prevent burning the patient) one on each pectoral and 2 hand warmers on their back over the kidneys.
To raise their blood temperature, place a hand warmer on the inside of each wrist with the length of the hand warmer going down the arm from the wrist and secure them so they do not fall off with tape or cloth. Now that you have done that place a hand or foot warmer under each feet and secure those in place as well. If you have any hand warmers left place one slightly under the groin area (femoral artery) going down the leg. Last put a wool hat over the patient to prevent heat loss from his or her head and enclose them in the sleeping bag or solar blanket (best if you use both). Make sure they cross the inside of their arms against their body so the hand warmers on wrists also heat part of their core.
Now that you have done all that your next steps is to create a fire near the hypothermic individual. This is not only to warm the patient up but to heat up water, & rocks.
The purpose of heating up the water is to not only hydrate the patient but to warm the patient up from the inside.
Once you have a roaring fire and heated the water up (the intent is not to have the liquid at the temperature of a hot cup of coffee of 160 degrees F, but rather 100°-120° F max) try to get the person to drink the water (sip slowly). It is at this point that you can wrap yourself in the bag with them holding them against yourself.
Explanation of the above.
The hand warmers are being used to heat up the persons core (chest area & all the major organs) and are being used to heat up their blood. Placing the hand warmers over the wrists, under the feet, and groin area is to raise the temperature of their blood. The radial artery runs down from the wrist and the femoral artery runs down the leg from the groin, and the plantar arteries are located under the feet.
This technique is proven to be much more reliable than simply lying down in your skivvies next to a person suffering from hypothermia and can be the difference between life and death. It is a technique that I have not only taught but practiced in real life including with my Ex who was suffering from hypothermia during a kayaking adventure in winter in Port Washington Harbor, NY which occurred from her refusal to wear my waterproof clothing.
If the person was in a hospital being treated for hypothermia, the Doctors would be using heated blankets, The Buddy Lite™ or the Hotline ( device used to warm blood and fluids), heated and humidified oxygen, warm IV fluids, and in more severe cases, peritoneal lavage (you don't want to know).
Realize that using your body heat to heat up the patient Will Not successfully
heat up their blood for severe hypothermia, and the average person body temperature is 98.6 degrees F. while the average hand warmer gives off about 135 degrees F. of heat.
It is also kind of like being on an airplane and the Oxygen masks fall down. You are supposed to put the mask on yourself first and then on your child or a passed-out passenger.
When a person is suffering from hypothermia, once they are dried up and have the handwarmers doing their thing, your best use is to make a fire and heat up liquid vs lying down. In severe cold conditions, chances are by not having a fire and lying down next to them that your core body temperature will fall too low too and, in the end, someone is digging 2 graves vs. 1
editor's note: As mentioned above, drinking warm/hot liquids can warm up the body from within. A military medical tactic that has also been used is having a very warm enema to warm the patent rectally on top of drinking hot beverages..
I would also like to point out, that hypothermia is very painful. The body can convulse so vigorously that you can even break bones.