Left MacBook in a cold car overnight

About all you could do initially woud be to put the computer in a sealed plastic bag, and then take it into a warm living area, to let it slowly reach room temperature without condensation forming inside the computer...

That could take days, and then there still could be moisture inside the computer housing from the cold incursion. Same kind of issue if you leave a digital camera in a cold environment, or other electronics, would be to contain it while it is cold inside a plastic bag, and let it warm slowly to the room temperature so that when you finally do open the bag, condensation or moisture will not form on the outside (or inside, unseen) of the product case.

Also, if the unit has a removable battery (several later models do not have one) you could remove the battery from the computer and then let it sit at room temperature a few additional days before attempting to use it. -- This, after waiting until the unit is warmed up in the bag.

Even so, after that, there could be other problems with the unit.

Or you may have dodged incidental damages.

Good luck & happy computing! 🙂

Do NOT place in a plastic bag as this may cause condensation.

Allow it to warm up in a warm (but not hot) dry room for a day or so, then recharge the battery.

If it does not perform as expected, take it to an Apple Store for a free diagnostic.

Seemed to work fine for mine, but your mileage may vary...

If the computer was kept in a padded case, let it warm up

in that case. It could still condense. Electricity doesn't like it.

iBook white G3, iBook white G4, Macbook... and two

digital cameras, plus a dozen film cameras with electrics.

The trick is to have the product in plastic before it freezes.

I've lived in arctic weather for 1/2 of 50 years.

{To consult an Apple Store Genius &/or product Specialist

probably would be advisable, and until you get an answer,

maybe just keep the computer in your freezer.}

Good luck & happy computing! 🙂