Solar-powered lunchbox keeps your food hot or even cool, depending on what's inside - Yanko Design
Amazon.com: HONEYBEAN HOME Battery Powered Lunch Box for Work With 35 Minutes of Heating Capability – Comes With a Reusable Fork & Spoon: Home & Kitchen
Hot Bento - Self Heated Resuable Lunch Box and Food Warmer, Battery Powered, Portable, Cordless, Hot Meals for Any Occasion, Very Perri - Walmart.com