I get overheated very easily when I am outside in the heat. I get a headache which leads to nausea and vomiting. The headache is throbbing. I have gone to the ER 5 or so times for this over the past 8 years for this and they give me IV fluids and anti-nausea medication. It seems to be getting worse, coming on quicker with less time in the sun. I have racked up some heavy medical bills because of this. I have a 3 year old and we live in Texas so I can't avoid being in the sun in the summer! I know I don't drink enough water, but there has to be something else I can do to avoid this.