Hi I've been training for a half marathon. I've been running twice a week since December and all of a sudden I'm getting a tingling sensation on my head when I run. Had anyone experienced this at all? It has happened the last 2 times I've been running. It doesn't happen any other time. The first time it was on my forehead and today it started at the back and went to my forehead. I hadn't eaten alot before hand but I had been drinking water and I had a meal about 2 hours before. Wondering whether to her get it checked or put kt down to maybe dehydration or pushing myself too hard.