Travelers Medical Guide

remain still in a position that minimizes your exposed surface area. Pull your knees together and up to your chest in what is known as the heat-escapelessening position (HELP) or the rescue position; it provides improved protection of the body’s high-heat-loss areas, which are the armpits, groin, chest and thighs.

Immersion-related hypothermia can also occur in relatively warm or even tropical waters as a result of the body slowly cooling over time. This may happen if you are in water as warm as 84°F to 91°F (29°C to 33°C) if you are not wearing any thermal protection. In such circumstances, you may not be aware of the slow heat drain for some time.

Hypothermia can also occur in surface or land settings.

The same factors — including the temperature of your environment, the presence of wind and how appropriately you are dressed for the conditions — are key in whether you are likely to develop hypothermia and how soon it might happen. Similarly, even a slightly cool temperature can result in cold stress, depending on an individual’s age, health status, body-fat ratio and body mass.

Symptoms: The signs and symptoms of cold stress vary according to how severe the condition is. Table 9 describes the various gradations of hypothermia.

Treatment: Individuals with mild hypothermia will be awake, conversing lucidly, complaining about the cold and probably shivering. Assuming no other injuries are present, mildly hypothermic victims can be rewarmed with a variety of passive or active techniques and with minimal risk of complications.

If travelers suffer hypothermia in a remote setting, many rewarming options, particularly more aggressive and invasive techniques, likely will not be available; nevertheless, rescuers must do what they can to protect victims from further injury.

The essential first step is to remove any wet clothing and replace it with a dry insulating inner layer and a windproof outer layer, including covering the head. Shivering can provide effective rewarming in cases of mild 126