This is why every party should have an Everburning Torch or two.
Without a doubt one of the most useful magic items in comparasion to its price.
I'd vote for "lightbulb-like"... I think of them as a stick with a metal ball on the end. You hit the ball against something and it glows very brightly... AHEM, like the sun. The glowing ball wouls be warm or even hot to the touch, but never hot enough to ignite anything. Once lit, you could stick it in your backpack, but keep it away from the chocolate bars.