Heated or not, condensation in the upper cylinders may have caused some rust to form on the piston rings and other steel parts. These minute rust particles can be highly abrasive and cause damage.

To minimize this, remove the spark plugs and spray into the holes a small amount of high quality motor oil such as Mobil1 5w-30. Do not replace the spark plugs, then with the ignition disabled, crank the engine for 2 seconds, pause for 5 seconds; crank for 3 seconds pause for 5 seconds; and crank for 5 seconds. This will help pre-lubricate surfaces that have become "dry."

Then replace spark plugs and you are ready to go. Keep speeds below 10 mph if tires have developed flat spots, until they are gently warmed up and rounded out. Drive the car for several hours to flush out any pooled contaminant moisture, acid, or particles, Have the oil and filter changed before they can cause any damage.

Note: Removing the spark plugs is an involved procedure. Do a search on "changing spark plugs on g37" to view the steps.