increasing heat causes thermal expansion
heat_of_formation is heat. heating_extra_heavy_crude is heating_hydrocarbon. heat is what_makes_hot. thermal_modification is heating. friction has effect_of_increasing_temperature heating_extra_heavy_crude is temperature_change. heating_extra_heavy_crude is heating. thermals is rising_currents_of_warm_air. overheating is heating. geothermal_energy is heat.