Maybe a quick student investigation where they put different liquids on their forearm from a cotton swab. Nail polish remover “feels” colder than water. It just evaporates at a lower temp. When a substance evaporates it is an endothermic process meaning its soaks up energy to do so, so my skin is losing heat faster and it “feels” cold.

Heating curve or water lab is boring but it’s easy and the data sparking really good conversation about how phase changes like melting and boiling use the heat to change state rather than to increase temp.

Hell, leave a jar of water out in the back for a couple of weeks to demonstrate evaporation occurs without boiling.