Having a good fire to keep you warm all night, especially if you would be cold or wet otherwise, is an invaluable skill to have in any survival situation. The Finnish Gap Fire is the ideal candidate for this purpose. You can learn how to build one below.

Building a Finnish Gap Fire is as simple as stacking two logs on top of one another and building a fire in between. No sawing into smaller chunks, no  splitting the logs, just a few minutes to clear the area of debris and lighting the flame.

You can make this an even easier process by using the hot embers from your cooking fire to place in between the two logs, rather than building a whole new fire. Next thing you know, you're toasty warm all night long.