By Neal W. Pollock, Ph.D.
Imagine standing on the deck of a boat speeding through cold waters at night. Or perhaps you’re night fishing and slip off the pier into frigid waves. As you sink into the water you’re momentarily stunned, shocked by the sudden change in temperature. “Get out!” your mind screams, as you gasp and begin to flail…
Don’t panic, but do try to get out of the water as quickly as you can. And if rescue is not immediate, read on for some helpful advice on what to do until help arrives.
Cold water can be a big motivator: if you fall in with less than adequate thermal protection, you’ll want to get out as quickly as you can. And the quicker you get out, the better for you. When you do get out, replace your wet clothing with dry, insulating layers and a windproof outside layer. Fortunately, this is generally adequate management.
But, like the person who falls from a moving boat, what if you can’t get out right away? And what if your chances of rescue are not immediate? In this instance, you must take steps to retain body heat. This is much easier if you are wearing a flotation device: not only will such devices provide some thermal protection (the amount can vary with the design), they help you to maintain a position that can further minimize heat loss.
This position, known as the “HELP” (Heat Escape Lessening Position), has the body upright, head out of the water and knees up to the chest. Hands hold the outside of the knees to keep them together while the elbows are kept in as close as possible to the body. If adequately supported by a flotation device, this position will provide substantial protection of the head, chest, armpits, groin and thigh – the major areas of heat loss.
Keep in mind that the bulk of clothing and lifejacket can make the hand and elbow positions difficult to maintain. If you can sacrifice some clothing with minimal heat loss cost, this can help. Holding or stretching a pair of socks across the knees will allow you to support the knees while keeping the elbows tightly tucked in. The key to an effective HELP is to maintain the position tightly and continuously.
The group version of the HELP is the “Huddle” position. Most likely to arise in the case of a vessel sinking, the group forms a circle facing inwards, with each individual maintaining as close to a HELP position as possible while holding onto the person of each side. The Huddle position has the additional benefits of greater stability than a single person in rough water, and it keeps the group together.
Rescuers removing individuals from the water following relatively prolonged immersion should be aware of a secondary risk: it is not uncommon for a sudden physiological crash, sometimes fatal, to be associated with the rescue effort. This “circum-rescue” or physiological, collapse, may be caused by a combination of the loss of water pressure supporting the body as the victim is removed or the circulatory response to physical manipulation during the rescue.
Recognizing this possibility is important. Vital signs must be carefully assessed throughout and following the rescue as circumstances allow. The best way to minimize the risk of circum-rescue collapse is to remove the victim gently and in a horizontal position, if possible.
Further descriptions of circum-rescue collapse can be found in these publications.
- Golden F St.C, Hervey GR, Tipton MJ. Circum-rescue collapse: collapse, sometimes fatal, associated with rescue of immersion victims. Journal of the Royal Naval Medical Service 1991; 77: 139-149.
- Winegard C. Successful treatment of severe hypothermia and prolonged cardiac arrest with closed thoracic cavity lavage. Journal of Emergency Medicine 1997; 15(5): 629-632.
About the Author
Dr. Neal Pollock is a physiologist working at the Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center.
(c) DAN – Alert Diver July / August 2004