In cold-water immersion, rapid cooling increases the risk of which condition?

• A. Hyperthermia progression
• B. Respiratory compromise
• C. Need for continuous monitoring and careful rewarming
• D. Arrhythmias

Answer: (D)

Rapid cooling challenges the heart’s electrical stability. As core temperature drops quickly during cold-water immersion, the heart’s conduction system slows and becomes electrically irritable. This can lead to dangerous rhythm disturbances, especially ventricular fibrillation or other arrhythmias, with the highest risk during deep hypothermia and the later rewarming phase when electrolyte shifts and catecholamine surges occur. Because of these factors, arrhythmias are the primary concern when cooling is rapid, making careful monitoring and gradual rewarming essential. While respiratory issues and the need for monitoring are important in cold-water rescue, the specific risk that rises most with rapid cooling is the heart’s propensity to develop life-threatening rhythm problems.