Dubai: It began as a lesson in saving lives — and suddenly became a real-life emergency. At a training class in Appleton, emergency medical instructor Karl Arps was demonstrating the signs of cardiac distress to students when he unexpectedly went into cardiac arrest — collapsing in front of the very class he had been teaching. What happened next turned a classroom exercise into a remarkable story of skill, speed and survival. Arps’ students quickly realised the emergency was real, began chest compressions, used a defibrillator and followed the exact life-saving procedures he had spent months teaching them. Their swift response restored his pulse before paramedics arrived. The irony was striking: a man teaching CPR survived because his students knew exactly what to do. According to The Washington Post, said students initially thought Arps’ gasping and collapse were part of the lesson scenario before recognising he was in genuine distress.…