increasing heat causes thermal expansion
thermals is rising_currents_of_warm_air. heat_of_formation is heat. heating_extra_heavy_crude is not temperature_change. thermal_modification is heating. heat_of_formation is not heat. heating_extra_heavy_crude is heating. friction has effect_of_increasing_temperature heating_extra_heavy_crude is temperature_change. thermal_modification is not heating. geothermal_energy is heat.