The correct answer is: Rainbow Push Ups.
Our AC in the car was dead and I had to go to Gunnison (about 15 miles) to drop something off at someone's house (they weren't there) and it was BLAZING hot. When I got there the boys faces were dripping with sweat (despite the ice water in sippy cups and cold wet washcloths that I gave them for the heat) so on the way home I bought them each a Push Up. There was no complaining on the way home, but there was quite a mess to clean up when we got there. At least I didn't feel like I was torturing them on the way home.
What measures have you taken to get the kids to stop crying?? :)