A lady with a history of manic-depression jumped 75 feet of a bridge into a river covered with two layers of ice recently. Although the jump was witnessed and the police were on the scene quite quickly, it took them about fifty minutes to safely get her out of the river into the ambulance.
She broke through the first layer of ice and went halfway through the second layer into the icy water. Her pants were wet, her coat less so. She had no memory of the jump and sustained open fractures to both legs and her humerus. She needed bilateral chest tubes and had a serious unstable spinal fracture. For hours it looked like we would have to amputate one leg below the knee; in the end we took her to the operating room and fused both her ankles before sending her to the neurosurgery team in another city.
What I don’t understand about her is that her core body temperature was normal (37.2C rectally) despite being in 1C water for more than 45 minutes on a day when it was about 0C outside and with considerasble wind. Any stabs at an explanation?
Remember the BBC series called “The Human Body”? The presenter, Robert Winston, followed this series with another which looked specifically at physiological response to a number of variables.
In one episode, he demonstrated homeostasis of core temperature by stripping to a pair of boxer shorts and subjecting himself to an hour inside an icehouse. I don’t remember what the air temperautre was, but it could not have been much colder than -4 or -5 centigrade.
He monitored his core temperautre on regularly throughout, and at the the completion of the hour, his core temperature was only one degree below the orignal, which was taken while he was still fully dressed.
However, apart from describing the usual resposes (pyloerection, vascular constriction, shivering etc), he did not go on to explain why the body maintains core temperature so well.
I studied thermal physiology in divers while an engineering student working for the summer for the Canuck military. Temperature plays a role in lowering the core temperature in accordance with Newton’s law of Cooling. Buit there is a big difference between being in, say, 10C air and 10C water since the mechanism of heat transfer is quite different. That said, the difference between being in an icehouse at -5C would result in a lot less heat loss than being in water at 5C for an extended period of time.
In fact, oen of my experiments showed being in 5-7 C water for as little as 10 minutes can lower core temperature by more than one degree.
Another cool experiment showed core temperature can be maintained in a cold wind tunnel in nekkid soldiers by applying electric heat to just a few small key areas.
Eh, Dr.P, if I’m reading your description right, only her legs were in the water. Her torso wasn’t. So her body core temperature never would have been under any serious threat. Just her legs would have been cold, when her body shut down the circulation to them. “Hello, Central, no blood’s getting’ through…” “Okay, then, shut 'er down, Jack…”
The concern about hypothermia and falling into icy water is when your whole body is soaking wet, including your torso (your “body core”).
Yes and no. Her waist was in cold water, it was quite cold outside and the ice had lacerated her coat which was damp if not soaking. Your point is taken but ovwer an hour I would have expected more of a drop.
Perhaps she wasn’t n contact with much liquid water, but mostly with ice? Not having the convection, ice will carry heat away far more slowly than will liquid water.
Just a WAG: Was the coat still down over her hips? That could maybe act like a scuba diver’s wet suit by stopping the water from circulating, so the water in contact with her body would warm up.
She was 35 or so. Her face was not wet. I heard about the site where she jumped off the bridge second hand and don’t know further details. Her blood vessels were clearly peripherally shut down. She had an open area with exposed bone and tissue the size of a 3.5" floppy on both shins.
Could be, but that doesn’t usually do the trick, and the ambulance attendants were baffled by it too. Congrats on wasting your 1500th post on this, though!