How hot was it?

From Washington, D.C., at a meeting of the American Chemical Society

HOT STRIP. When exposed to boiling temperatures and then cooled, a dye-riddled polymer strip changes from green to orange. Weder

Scientists have created heat-sensing polymers that indicate exposure to high temperatures by changing color under ultraviolet (UV) light. If built into food and medicine packaging, such materials could serve as indicators of spoilage.