In the wild without it can get cold, very cold. So take a bit of vaseline and cotton balls next time you go on a camping trip:
The easiest way to start a fire, obviously, is a light but there are other ways too: Using cotton balls and vaseline for instance and it also works in the rain.
The materials you need are as follows:
Vaseline (petroleum jelly)
100% cotton balls (no synthetic)
Some scissors or kitchen sheers to cut the aluminum.