Of course, this seems pretty obvious and if you know the very basics of grilling you shouldn't have a moment's trouble. However, people don't often think of a backyard grill as a backup cooking appliance for when others are unavailable. Because of this most people will make some basic mistakes. I've compiled the following list of rules and tips to help keep things safe, since some mistakes can be very deadly.
One: Outdoor cooking equipment must stay out-of-doors. Never bring a gas or charcoal grill inside of your house or use it in an enclosed space. These units can create a great deal of carbon monoxide which is undoubtedly unsafe. Every year dozens of people die from carbon monoxide poisoning while using a grill indoors or in an enclosed space.
Two: Always make sure you have enough fuel. For the typical gas grill a full propane tank will give you enough fuel to cook about 30 to 50 meals. One full tank will keep you grilling three meals a day for at least 10 days. Sounds good, but how much propane do you have in your tank right now? Not sure, don't bet on there being enough. It is always a good idea to have a spare full tank at all times. The tank you fill is not the one you need, it's the spare. Store your spare tank in a protected but not enclosed place, especially not in your house. As for charcoal, a 20 pound bag of briquettes should get you through at least 4 to 6 cookouts. If you are betting on using a charcoal grill in an emergency situation, make sure you have at least two 20 pound bags.
Three: Have the right cooking tools and equipment on hand. Sure, you can always throw some burgers or chicken on the grill when the lights go out, but how about boiling water? Many of the pots and pans we use today have wooden or plastic parts that will burn or melt if placed inside a grill. If you have a gas grill with a side burner then you are fine and should use the side burner as much as possible. A 12,000 BTU side burner is going to use a lot less gas than turning on all the burners in your 40,000 BTU gas grill. You can place most pots and pans on the side burner to boil water or heat up a can of soup, but if you don't have a side burner then you will need to place pots and pans inside the grill. Having at least one large saucepan and one skillet that can be used on a grill will give you all the versatility you need to prepare almost anything. If you have camp cooking equipment this is perfect. Also remember that in some emergencies it might be necessary to boil all the water you drink. This will require a large pot and plenty of fuel.
Four: If you don't know how long you are going to be in the dark, conserve early. Don't burn up fuel and food in the first day if you are unable to replenish your supplies for several days. Use fuel sparingly by not preheating for more than five minutes and make sure you turn off the gas before you are done. Gas grills maintain heat for a few minutes after the fire goes out. Use this time to finish up. When using charcoal, light only as much as you need. You can add coals a few at a time if you need more heat or if you need to cook for a longer time. Also plan on heating everything you might need all at once. Most grills have large cooking areas so you can have a pot of two of water going while you cook other dishes. But make sure that you maintain a high level of food safety. Be sure that everything which comes in contact with raw meat is heated to at least 165 degrees.