What is the maximum time food must be allowed to cool out of as refrigerated unit?

Food doesn't specifically have to be cooled in a certain time. Food must be covered once it has cooled however, so don't leave it out for more than a few hours.

ANSWER:

For safety reasons, food must be cooled within 4 hours, otherwise pathogens can grow and make the food unsafe to eat. Never leave any food out of the refrigerator for more than 4 hours as well, for the same reason.