Is it possible for dove eggs to be out of the nest for a day and be hatched under a heat lamp?

It depends on the conditions when they were unprotected. All you can do is try. Keep the temperature above 80 and less than 100 degrees F. USE A THERMOMETER! Gently turn the eggs every day. Heat lamps are dangerous, as they can build too much heat quickly. A light bulb in a reflector is safer.