Plot the average value of a parameter across a geometry component

Hello,

I have used COMSOL (5.3a) to solve a time-dependent 3D heat transfer model. I am trying to plot the average temperature of a specific object in my geometry over time. A 2D graph, with time on the x-axis and temperature (averaged) on y-axis. Can someone explain how to do this?

I have done something similarly but plotted temperature at a point, using a point probe described here. Is the solution similar?

Thanks for your help everyone.