Yes, it's possible with APDL commands. The general technique is to break the solution into many short time steps. At the end of each time step you can query the model temperatures and apply a heat flux or flow based on a formula or table using a Commands Object that is to be executed every step (assuming you are in Workbench.) For example:

...

SOLVE

temp_1 = temp(node(x,y,z))

temp_2=temp(node(x,y,z))

sf,named_selection,hflux,100*(temp_2 - temp_1)