Rough question: Does applying grease to your body before going into lethally cold water, as in a ship sinking in the North Atlantic Ocean in Winter, actually give you any survival advantage?
1.) I have read several separate accounts by survivors of torpedoed ships in the Atlantic Ocean during WW II in which prior to going into the water the victim applied some sort of grease to his body (type unspecified) in the belief that it would hold-in heat and increase his chance of survival. Each swore this had saved his life.
2.) In researching this online, I find conflicting information. The technique seems to relate to long distance swimming, such as the English Channel. Some experts say the right kind of grease (lanolin or vaseline), or the right mix of these, and careful application to particular areas of the body, is of benefit for distance swimmers in cold water. Others say, all in all, it is more trouble than it is worth, giving little or no advantage, and, improperly done, is a distinct detriment.
3.) The only explanation having to do with preserving core body heat said this: That the body NEEDS the shock of cold water to close off the vascular system in the extremities (arms and legs) in order that the vital core of the body (trunk) will hold in the heat it has longer, increasing the time you can function (or survive) in cold water. Grease will prevent this closing off of the extremities, making loss of heat from the body core happen more quickly.
Is there any survival advantage for a sailor spreading some type of available grease on any portion of his body prior to leaving a sinking ship in an extreme cold water environment, such as the North Atlantic in Winter or the icy Barents Sea on the run to Russia?