I have a CAH - saltwasting son (age 9) and a non-CAH son (age 12).  Both of my sons are very active..swimming (almost every day), baseball, basketball, football, camping etc.  I make sure both of them drink LOTS of fluids but there have been a few times when my CAH son has shown signs of "too much heat".  He's getting old enough now that he knows these signs and gets in airconditioning...however when he was younger I had to judge by his look and how he acted.