Definatly bring in a fecal (hopefully not one more then 24 hours old, not the easiest feat) (keep the fecal sample refrigerated, not frozen, untill you can bring it in) I am sure you can always bring in a fresh sample to drop off if he doesn't go in time for the appt. Bagging him should be fine, I find that the best way to transport. As for heat pads etc, just make sure it is warm enough, I don't know what your weather is like etc.
But good for you for bringing him to a vetrinarian.
Thanks
Rusty