Usually not -THAT- hot anyway. They usually run pretty cool. Could be the new spindle isn't seated in yet and it will break in and settle down once its run in for a couple hours, but likely not. You may have just gotten a bad spindle bearing or something. Check to make sure you don't have the belt massively overtensioned, but beyond that just run it in and hope for the best.
Taig is pretty good about replacing that stuff if it is actually a manufacturing issue. I had a bad Z carriage block on one unit a long time ago, it had one minor tolerance issue that kept the gib from seating correctly. They sent a new one out right away.