Thermal barcodes

Food safety technology is making great strides these days – an "unnamed retailer" operating in the US and Europe is going to trial a barcode that monitors product temperatures. The heat-sensitive invisible ink behind the barcode changes color (becomes visible) when it gets too hot, making the bar code unusable. That makes the barcode impossible to scan, which makes it a lot harder for you to get salmonella or tapeworm. From the grocery store, anyway.