You are correct, the most effective treatment for warming a crew member suffering from hypothermia is B) bundling the body in blankets to re-warm gradually. The key reason this is the correct answer is that rapidly rewarming a hypothermic individual can be dangerous and lead to further medical complications. Gradual rewarming by insulating the body with blankets is the safest and most effective approach, as it allows the body to naturally restore its core temperature at a controlled rate. The other options are incorrect because A) rapidly rewarming with heat lamps can cause shock, C) increasing circulation through exercise can further deplete energy stores, and D) rapidly raising body temperature with hot water can also lead to dangerous complications.