The cold remains a mystery, more prone to fell men than women, more lethal to the thin and well muscled than to those with avoirdupois, and least forgiving to the arrogant and the unaware.
The doctor rapidly issues orders to his staff: intravenous administration of warm saline, the bag first heated in the microwave to 110 degrees. Elevating the core temperature of an average-size male one degree requires adding about 60 kilocalories of heat. A kilocalorie is the amount of heat needed to raise the temperature of one liter of water one degree Celsius. Since a quart of hot soup at 140 degrees offers about 30 kilocalories, the patient curled on the table would need to consume 40 quarts of chicken broth to push his core temperature up to normal. Even the warm saline, infused directly into his blood, will add only 30 kilocalories.
Ideally, the doctor would have access to a cardiopulmonary bypass machine, with which he could pump out the victim's blood, rewarm and oxygenate it, and pump it back in again, safely raising the core temperature as much as one degree every three minutes. But such machines are rarely available outside major urban hospitals. Here, without such equipment, the doctor must rely on other options.
"Let's scrub for surgery," he calls out.
Moments later, he's sliding a large catheter into an incision in the man's abdominal cavity. Warm fluid begins to flow from a suspended bag, washing through his abdomen, and draining out through another catheter placed in another incision. Prosaically, this lavage operates much like a car radiator in reverse: The solution warms the internal organs, and the warm blood in the organs is then pumped by the heart throughout the body.
The patient's stiff limbs begin to relax. His pulse edges up. But even so the jagged line of his heartbeat flashing across the EKG screen shows the curious dip known as a J wave, common to hypothermia patients.
"Be ready to defibrillate," the doctor warns the EMTs.
For another hour, nurses and EMTs hover around the edges of the table where the patient lies centered in a warm pool of light, as if offered up to the sun god. They check his heart. They check the heat of the mattress beneath him. They whisper to one another about the foolishness of having gone out alone tonight.
And slowly the patient responds. Another liter of saline is added to the IV. The man's blood pressure remains far too low, brought down by the blood flowing out to the fast-opening capillaries of his limbs. Fluid lost through perspiration and urination has reduced his blood volume. But every 15 or 20 minutes, his temperature rises another degree. The immediate danger of cardiac fibrillation lessens, as the heart and thinning blood warms. Frostbite could still cost him fingers or an earlobe. But he appears to have beaten back the worst of the frigidity.

