In a computing context, ambient temperature is the air temperature of any environment where computers and related equipment are kept. The adjective ambient means "relating to the immediate surroundings."
Maintaining an appropriate ambient temperature is crucial to the proper functioning and longevity of computer equipment. In general, a safe range is between 60 and 75 degrees Fahrenheit, although the cooler end of that range is better. Ambient temperatures above 80 degrees make it difficult for a computer's cooling system to keep it at a safe operating temperature.