I assume you mean "sake" which is a kind of wine brewed from rice.
It can be served either hot or cold.
But the top quality, fresh one should be serve cold, not to kill its nice flavour.
If you drink sake outside, it is normally treated with heat to prevent its fermentation (otherwise the sake will go bad during transportation or storage). In that case, you can enjoy it either way. If you come to Japan, you should try "nama" (means "fresh"), which is usually chilled. It's very good.