Survival in cold water.

In recent years the increased interest in small boat sailing and inshore recreational activities, as well as a number of major disasters at sea, have drawn attention to the need for all concerned to be familiar with the basic problems of survival in the water. Unless a man is supported by some buoyant object -ideally a life jacket-and is quickly picked up or reaches shore, he will drown. Though ability to swim well improves the chances of survival, Dr. W. R. Keatinge and his colleagues rightly point out in their paper at page 480 of the B.M.7. this week that swimming in cold water may indeed lessen the chances of survival. L. G. C. Pugh and 0. D. Edholml have reported that a relatively thin man could lose heat more rapidly if he swam than if he kept still supported by a life jacket, and Keatinge emphasized the role of hypothermia in causing death when the Lakonia was abandoned at sea.2 The present teaching is that people who are thrown into water should stay put until picked up, provided they have adequate support such as a life jacket or floating wreckage. Swimming should be strictly limited to reaching nearby objects such as rafts. Further advice to people about to leave a sinking ship or who are sailing a small boat with a risk of capsizing is that they should put on as much clothing as possible or wear accepted survival suits. This need is second only to the use of an approved life jacket. The findings in the present paper by Dr. Keatinge and his colleagues fully support this teaching. It is significant that the subjects of the experiments were clothed, and that the cold water in which they were immersed was at 4.70 C. (400 F.), close to that encountered round the British Isles in the winter months. The breathlessness caused by sudden immersion in cold water is well known, but it is believed that this is the first attempt to measure it, and the degree to which it occurs is remarkable. Hypothermia has always been regarded as a major hazard for the survivor in cold water. G. R. Hervey3 has stated that a lightly clothed man will not live more than 15 minutes at 0° C. (320 F.) and cannot maintain heat balance below 200 C. (680 F.). It is apparent from this new work that respiratory distress in a swimmer may shorten this period. Cases of sudden death on immersion in cold water have occasionally been reported as due to reflexly induced cardiac arrhythmias. The death is too sudden to 'be due to the inhalation of water, but clearly this is an additional factor in the causation of drowning. Though work in this field is likely to be limited because of the slight risk of cardiac failure on cold immersion the further study of the respiratory effects does deserve cautious investigation. The present paper is particularly welcome not only for its contribution to the study of survival but for its forthright emphasis on " the need for the occupants of small boats to wear a life jacket capable of keeping the face above water, and the danger in trying to swim even short distances to shore in cold water without one."