With students beginning school around the country, the number of brown-bagged lunches will tick up exponentially. Whether you’re preparing a sandwich for your kid or making your own midday lunch, there are a few food safety tips to keep in mind.

According to a recent Inquirer.net report, temperature control is key. Foods that are stored in the “danger zone” of 40°F to 140°F have a markedly better chance of harvesting bacteria than food stored below or above those temperatures. Since it’s unlikely you’ll be setting up a catering-style open flame for hot foods, make sure your meals are being refrigerated with either the paper bag or lunchbox left open to allow for better air circulation.

If you don’t have a fridge and have prepared perishable items like eggs or cheese, you can opt for an insulated box or double-thickness soft bag—avoid paper, a poor insulator—and use a frozen juice carton or ice pack to keep meals chilled. If you’re opting for hot foods like stews or chili, you can pour boiling water into a thermos and then empty it; the residual heat should keep the liquid warm until lunchtime. You could also buy a double-walled stainless steel container like this one, which will keep foods hot (or cold) for up to three hours.

Got leftovers? Toss them. It becomes harder to regulate temperature as the day goes on and foods may begin to slip into that illness-causing “danger zone” when left unattended.

For more food safety tips, check out the handy USDA infographic below.

A USDA food safety infographic
USDA, Flickr // CC BY 2.0

[h/t Inquirer.net]