Carbs ans sugar based candies will give you a short term lift. Something you might want in an emergency. But long term like an overnight stay in the cold weather situation you need fats and protein.

A couple of power bars would not be a bad start. But in thecold they get very hard to chew. Hard candy is always a compact package for a boost.

Traditionally pemican has been the food of natives and frountersmen especially in the cold months. Dried meat, dried fruits or berries and rendered fat as a binder and coating. Fry up a couple of slices and when you are cold you would be suprized how good it tastes. Your body knowes what it needs.I've seen a recipe that substitues peanut butter for the fat.

A modern partial substitute is peanut butter. Plenty of protein and fat to fuel the body. There is also the choice of natural peanut butter without all the additives. For that matter any nut can be ground into a paste or butter. A small jar would be good thing to toss in an emergency kit.

MRE's can come with a heating system for a hot meal if you can't build a fire.

Any kind of powdered drink mix, coffee or tea for a hot drink will work wonders on morale on a long cold lonely night.