I just googled and found this:
When trying to reduce a fever:
DO NOT bundle up someone who has the chills.
Remove excess clothing or blankets. The environment should be comfortably cool. For example, one layer of lightweight clothing, and one lightweight blanket to sleep. If the room is hot or stuffy, a fan may help.
A lukewarm bath or sponge bath may help cool someone with a fever. This is especially effective after medication is given -- otherwise the temperature might bounce right back up.
DO NOT use cold baths or alcohol rubs. These cool the skin, but often make the situation worse by causing shivering, which raises the core body temperature.
Drink cool liquids, as tolerated.
http://www.thedenverchannel.com/encyclopedia/6863861/detail.html
Now you are NOT supposed to dunk them in icy water because the temp drops too fast. You sponge them down with cool water.
I only know because my middle son ran those scary high temps!
I'm trying to remember, but isn't rubbing alcohol better for bringing the temps down?