My military unit moved into a newly renovated building a couple years ago. In order to save energy, it had one of them new-fangled centralized-controlled HVAC systems.
Each office had a temperature sensor but no thermostat that could be set. The usual 'heat on way too early in the fall' stuff, as well as the 'indoor temp set to 80F in the summer' applied.
As the commo guy for the unit, I took it upon myself to open up one of these sensor, and found it contained a simple, exposed thermal resistor. I figured out that hotter temperatures lowered the resistance, and quickly tested my theory by shorting the circuit to kick on the AC.
But, a long term solution needed to be non-obvious, and a 100% temperature reading was going to be obvious. So I did the math, and added a small resistor in parallel to the circuit, basically convincing the central computer that it was always 10 deg F hotter in my office than it really was.
I had the coolest office in the building, until my bosses figured out that I had done something; I then I had to replicate my efforts in their offices.
This would make an excellent bonus question on an EE101 exam.