I seem to be getting some REALLY nasty headaches during and after my burpee sessions. Today in particular I was going pretty hard, my HR was around 180 bpm and I started to feel some strain at the nape of my neck. Soon after the pain moved to the top of my head and I was forced to stop and lay down. I still feel it even now and if I bend over it gets worse. Anybody else suffer from this? How did you remedy it?