Steve,
I am trying to fix temperature in my simulation using fix temp/rescale and also want to calculate heat current which is equal to difference of kinetic energies before and after scaling summed over all the velocity scalings. The following is the part of the code used to scale and output the energy values.
I am not using NVT at all in this code. I am using NVE to update positions and velocities.
fix 3 all temp/rescale 1 350 350 0.3 1.0.