Most Red wins are best served at room temp. However if you do want to chill it I would put it in the fridge for no longer than 30 minutes then take it out and serve it.
Quite simply, unwooded Chard or "unoaked" is wine that has never seen the inside of an oak barrel. Typically it will be wine that is fermented in a stainless tank, as opposed to a wooden (oak)...