Thermal Physics covers temperature, the states of matter, and how heat is transferred.
Heat travels by conduction (through solids), convection (through moving fluids) and radiation (through empty space, like the Sun's heat). Heat always flows from hot to cold. Pure water freezes at $0°$C and boils at $100°$C.
Remember
- Conduction, convection, radiation.
- Water: freezes at 0 °C, boils at 100 °C.