What you can do is apply temperature load in 2 steps. The first step is of 2sec where a temperature of 220 is applied and looking at the above plot say the second step is of 80 sec. In the next step deactivate the temperature.
Apply the convection boundary condition for the second step (deactivated in the first step). This might give you the desired plot.
Right-click on the graph at a particular step and then you can activate/ deactivate the given step.