They are normally spongy so that part of it isn't a problem. But "cold" is relative. Are you talking about chilly but not frozen, or just slightly frosty, or deep freeze conditions? And how long was it "cold" for?

It was on a covered porch, the plastic sheeting fell. So was in just above freezing for 12 hours.

That's a long time for such low temperatures. If the plant was wet the cold penetrates much faster. If it was on the drier side then the effects might not be so bad. You can only wait and see. Keep it warm not hot, don't let it dry out but make sure it's not too wet either, and try to keep it where the relative humidity is higher.

The base of the plant is a mass of old sterile/shield fronds and roots. Inside that is the main rhizome of the plant from where all the fronds come. It's fairly well protected in there and so can cope with a bit of abuse. It's worth giving it a chance to recover. Good luck with it.

Thank you.