dilate; the dilated blood vessels then act as conduits for relatively warm core blood to be carried to and cooled by the periphery. A greater afterdrop has been seen in studies in which hypothermic subjects have been gradually rewarmed with increasingly warmer water, which causes greater vasodilation. Thus, from a practical point of view, the faster a hypothermic victim is warmed, the greater will be the afterdrop. Because the number of unknown factors is large, medical officers need to keep in mind that the rewarming of severely hypothermic casualties in the field might induce rewarming collapse
Another controversial area is the appropriateness of CPR in the field. As previously suggested (see Exhibit 11-5), there are times when CPR may not easily be implemented in the field. The first point listed, that the rescuers themselves should not be endangered by evacuation delays, should be emphasized.