noun: an uneducated, untrained or poorly trained individual placed in a given position in a workplace where he/she is neither technically capable of performing the required task nor performing any useful activity, but to deceive the observer in some manner. Warm bodies are often used to give the appearance of proper staffing, to make an organization look larger than it actually is during visits and official functions, or to fulfill some political agenda in the given organization (i.e. "diversity").
"Frank always uses his relatives as warm bodies whenever a customer visits the shop, to try to give the impression he has a zillion people working for him. He must have learned the warm body trick in the old country, when the Communists would take all 12 cars in town and park them in front of wherever they were filming propaganda movies, to make it look busy..."