The latest thing for coffee on the go is Wolfgang Puck’s gourmet self-heating coffee. Each self-contained, single-serving unit uses “the reaction of a natural mineral and water” to generate heat to warm the 10-ounce drink. No need for a barista, coffee maker, microwave or stove-top. We brought along a four-pack on a recent camping trip. The instructions are easy to follow and in the promised six to eight minutes, we held piping hot beverages in our hands — hot enough to make us sip slowly for fear of burning our mouths. The activation starts by pushing a button at the can’s base; a hidden central chamber heats rapidly and, in turn, warms the coffee. So the self-heating thing works. Unfortunately, the drink is sickeningly sweet — so sweet that most of the campers opted for gritty, open-fire brew instead. The drinks are sold at QFC, Fred Meyer and Big Kmart; four cans cost $9-$10. www.wpgourmetlattes.com