You might respond to your classmate with something like this:
"Wow, that's an incredible story! It's amazing how quickly you were able to respond in such a scary situation. I think many people would feel that initial panic, but it’s inspiring to hear how you managed to stay focused and act effectively. Your experience really emphasizes the importance of being trained in first aid and being prepared for emergencies. I’m glad the child was okay, and it must have felt great to know you were able to help. Have you considered taking more advanced first aid training or CPR courses? I think that could be beneficial for all of us!"