On aluminum block/head engines it's pretty darn bad to overheat. Warpage is the culprit. If ya are losing water, and the rad isn't leaking, I'd check those pesky head gaskets, or possibly a hose has gone to poo. Could be a number of things.
Running out of oil can do equal amounts of damage, but in different ways. Spun bearkings etc.
Both are really a no no, and should be avoided at all costs. Watch that temp gauge! If it's not working, fix it.