I am 14 years old, and today during gym I ran a lap, and just a minute later, my heart began to ache, and then my left arm started to ache, and began to go numb. I felt like I was losing balace, and stability. My friend had tooken me up to the nurse, and I sat down for a while and got some water, and I started to feel better. What happened? Heart burn? Early stages of a heartattack, or heat stroke? Please help. Do you know what I found? Get checked out by a doctor. That doesn’t sound right. It’s not heartburn (stomach acid).