I can't open the child proof cap, I push down and turn counterclockwise, but it won't open, even if I push down with it on the ground, and use a pliers handle to turn. It turns a little ways, but won't release from the bottle.

It is indeed a child safety cap. Run it under hot water for up to a minute, push down and twist. If it does not work, but a stick through the cap for leverage, and have someone else push down that way you can put all of your force into twisting.

Hand it to the kids, they always find a way to override that sort of stuff. Sounds like you did everything you were supposed to. Try this though- if you're at home, try to find something longer than the pliers handle like a long screwdriver or a dowel or something similar that you can slip through the cap's eye and bear down on with the palms of both hands. Something that won't break or bend. Set it on the ground between your feet and then push down evenly and try to turn it. In camp, use something like a good, solid x-peg stake, trekking pole tip, or a strong stick. That should do it, even if the threads are impossibly crossed. If not,except for cutting it off, I'm out of ideas. When you finally get it off, throw it away and use the stock cap. Tell the kids that if they even touch the bottle, they'll die instantly, or if they don't know how to read yet, show them the writing on the bottle and pretend to translate some arbitrary part of it into an ominous and terrifying warning. You would be surprised at just how effectively "childproof" both these techniques can be...my kids still have phobias about white gas and wild mushrooms.

Mary, I have had this problem before especially when it is cold out. I seriously had to bang the crap out of this thing on a picnic table to loosen the lid and after some serious down pressure and twisting till my fingers hurt it popped off. Take a look by angling the the bottle verticly. Make sure the threads are aligned and not cross threated. If they are trying hitting the lid with a hammer. Keep trying!

I'm very sure these do not have child safety caps. Are you sure the cap is not crossthreaded?