Most common school lunch ingredients can spoil, even over a short period of time. Cheese, cold cuts, dairy products and salads with chicken, tuna and eggs are all perishable.
Food that goes unrefrigerated allows bacteria to multiply. If lunch is going to sit out for a while, especially when temperatures are warm, consider insulated lunch bags (great for the environment) and cold packs. As a bonus, the food will taste better and increase the chance your child actually eats the healthy meal you prepared.
Check out the slideshow above for more school lunch safety tips.