In most cases, when you see a fire engine in front of a building, they are not shopping or conducting personal business, but they are most likely doing an "in-service" inspection or conducting a "pre-fire plan" of that particular building. There are over 2,600 business that must be serviced twice in this way each year. But in some cases, they really are shopping. Firefighters work a shift of 24 hours, from 7:00 AM till 7:00 AM the next day. This means that they are on duty for three meals not just one. They are allowed to make one trip to the store each day. This must be done on the fire trucks, but at all times, the crew is in instant radio contact with the 911 dispatcher and they stay in their response territory and are ready to go when needed.