The USDA issued a warning that “a minimum temperature of 135 degrees for a maximum of 8 hours, or a minimum temperature of 140 degrees Fahrenheit indefinitely, would also be adequate to ensure food safety. In fact, some ovens have a warm temperature, which is usually 170 to 200°F, or a heating drawer, which is designed to keep food at a warm and even temperature. Help protect your party guests by adapting their favorite recipes that contain eggs (or replacing some prepared products with some products). If your food was cooked to a safe temperature for dinner, reheating it and placing it in a thermos won't be a problem.
Packing hot and cold foods properly in a thermos is essential to ensure that foods are safe to eat when lunchtime rolls around, so let's review both methods. When it comes to packing milk, milkshakes or yogurt ice cream, as long as your food isn't kept above 40°F, you're good to go. Just like in an oven, if you plan to store food for more than an hour, you might notice a change in texture or flavor. If you need to keep food warm for a short time, simply wrap it up or cover it with aluminum foil.
You can use your kitchen appliances or insulated containers to keep food warm, use a cooler to make a portable, hot bowl, or serve food on hot plates so they don't get cold. For a longer time, check a food thermometer often to make sure that food stays at a temperature of 140°F or higher. Foods packaged inside any lunch box must be well cooked, so you should not eat raw eggs, onions, meat or fish that are not well cooked.