You are evacuating crew members from a survival craft that has been adrift in the North Atlantic for several days. What could occur if a person suffering from hypothermia is vertically lifted in a rescue sling to the helicopter?

Correct Answer: Option D — severe shock or cardiac arrest

Vertical hoisting of a hypothermic casualty in a rescue sling removes the hydrostatic pressure of the surrounding water and causes severe peripheral vasodilation and venous pooling in the legs. This sudden drop in central venous return can trigger circum-rescue collapse, resulting in severe shock or fatal cardiac arrest.