Call camera/lens.setThermalMeasurementMode to set the thermal measurement mode as ThermalMeasurementMode.SPOT_METERING.
Call camera/lens.setThermalSpotMeteringTargetPoint to set the measuring spot.
Call camera/lens.setThermalTemperatureCallback to register a callback to recieve an update of thermal temperature. A return callback will occur when the temperature of the specified spot is changed. Only the thermal camera has a firmware version which is greater than 1.20.0.00 supports this feature.