Prevention beats treatment, as everyone above has mentioned.

As Art said, forget the macho crap. Someone has to be conscious enough to call for help!

Know the symptoms, and watch out for them in yourself and others.

Keep more water with you than you think you'll need -- you might need to pour it over your head and keep bandanas and towels wet.

Don't forget about water toxemia (aka Hyponatremia), too much plain water at once. Carry some electrolyte/salt mixes (like dry GatorAde) or the premixed kind. You may want to dilute it a bit.

You can also make a kid-palatable electrolyte replacement drink at home (from baby parenting site

* 2 quarts water
* 2 tablespoons sugar
* 1 teaspoon baking soda
* 1/2 teaspoon salt substitute (potassium chloride)
* 1/2 teaspoon regular salt
* 1 package unsweetened Kool-Aid

Refrigerate and use within 4 days if you have to store it.

Sue