Do you get in your car, start it in 10 degree weather and FLOOR IT for a minute or two? Why not? (Because you'd seriously hurt the engine...)

Yes, you should be warming up your spindle. Start it at the lowest speed possible and let it run until the case isn't ice cold. Just let it run and go do something else for 10-15 min. The bearings are loose and sloppy when cold, just like an engine. When they heat up and expand, they can now hold tolerance. When they are run without warm up, the oil in the spindle is like candle wax - and it's completely possible to skid and gall the bearings...which ain't pretty.

Non ATC HSD spindle are thrown away when the bearings give out since it costs more to replace the bearings than a new spindle. Colombo spindles can be rebuilt, but even doing it yourself (ill advised) will cost you $800+ for the correct bearings and special grease, not to mention specialized tools and know how like dealing with the squirrely labyrinth seals...

So yeah...treat your spindle with care.

-B