Solar-powered lunchbox keeps your food hot or even cool, depending on what's inside - Yanko Design
Amazon.com: Electric Lunch Box for Car and Home Work, 12V 24V 110V 60W Faster Portable Food Warmer Heated Lunch Box for Adults, Removable 304 Stainless Steel Container 1.5L, Leak Proof, SS Fork
Hot Bento – Self Heated Lunch Box and Food Warmer – Battery Powered, Portable, Cordless, Hot Meals for Office, Travel, Jobsite, Picnics, Outdoor Recreation, Kitchen Meal Prep: Home & Kitchen - Amazon.com