Burn paper wrapped around stick and metal rod
boil water in paper cup, then try sand in the cup
Do same in styrofoam cup
Do the heat conduction contest with the device that has several different kinds of metal attached.
Temperature vs hot and cold

333 Tricks: pg 133 Expansion and Contraction:
Hang a weight on a wire so it barely swings above a table or floor. Heat the wire with a blow dryer and it will expand so that the weight drags the floor or table. Then, using ice cubes, the wire may be cooled enough to make it contract so the weight swings freely again.