At some point, you may have suffered from the nausea, vomiting and watery diarrhea that food poisoning can bring on. Other symptoms might include a fever and abdominal cramping. If your child eats spoiled lunch meat, his symptoms may begin within a few hours, or they might start days later, according to the Mayo Clinic website. A mild case of food poisoning might last a day or two, and a more persistent case could last for up to 10 days.

If your child eats spoiled lunch meat, he should feel better once the offending substance has cleared from his system. In the meantime, give him clear liquids until the worst has passed, then ease him back into eating with the BRAT diet, which consists of bananas, rice, applesauce, toast and other bland foods. As he begins to feel better, gradually introduce other foods to his diet. Avoid giving him dairy products and spicy or heavily seasoned foods for several days.

While most of the time food poisoning clears up on its own within a few days, there are a few symptoms to watch for that warrant a telephone call or a visit to the doctor. If he is not drinking liquids, he may become dehydrated. Symptoms include scant urine, a dry mouth and a headache. Since dehydration can become serious, call his doctor if you have concerns. Other reasons to call the doctor include blood in the diarrhea or vomit, watery diarrhea lasting more than three days, extreme abdominal pain and a high fever.

Keep your lunch meat refrigerated. If you have a picnic or a party, you can leave it out for up to two hours, then put it back in the fridge. When you pack your child's lunch for school, remember to include an ice pack to keep his sandwich fresh. Another option is to freeze a juice box and to use that as an ice pack. By the time lunchtime rolls around, the juice should be thawed but cold, and the sandwich will not have had time to spoil. Once you open a package of lunch meat, use a permanent marker to write the date on it. This will remind you to use it up or toss it in the trash within five days. If the meat feels slimy or smells funny before that, throw it away instead of packing it in the kids' lunches. "If in doubt, throw it out," is a good adage to remember; it's better to lose a few dollars in wasted lunch meat than to deal with food poisoning later.