Yep. Take a paper towel, soak it in cold water, drape it over the thermostat. Works like a charm. We used that in high school in the early '80s, but that wasn't an energy-crisis thing...that was a 1950s high school building that leaked cold air like a sieve!
}:-)4
Back when I was a kid the teacher used to send us outside to bring in snowballs to keep us warm.