Texas heat stroke!

I don't know why I continue to go out and try to play golf in dangerously high temperatures and high humidity. Yesterday we played 9 holes and ever since then I have been totally drained. Today was just a hang out at home in the recliner kind of day. I can't even blame my slothfulness on rain today because there was none. I see other people playing 18 holes with no problems. I want to do that as well, but it just isn't happening.