Generally and not exclusively, a method for controlling a process condition of at least one item within a microwave chamber may include receiving one or more initial values of one or more dynamically variable heatability properties for the at least one item in the microwave chamber, applying one or more microwave energy beams to the at least one item in the microwave chamber, remotely monitoring a spatial variation of the one or more dynamically variable heatability properties for the at least one item in the microwave chamber at least one of simultaneously with or following the applying of the one or more microwave energy beams, and estimating the process condition for microwaving the at least one item in the microwave chamber based at least partially on the monitoring of the one or more dynamically variable heatability properties for the at least one item in the microwave chamber.