COLD TO THE TOUCH THESE GIVE OFF NO HEAT. THIS LOT WILL HAVE “EXPIRED” DATES AMONGST THE TOTAL. LONG SHELF LIFE BUT THEY WILL LAST FAR LONGER THAN THE STATED EXPIRY DATE. AS MILITARY ISSUE THESE ARE VERY TOUGH AND VIRTUALLY INDESTRUCTIBLE UNDER NORMAL USAGE, UNLIKE THE CIVILIAN FLIMSY GLOW STICKS.