Sleeping outside, with suffocated hot coals under you sleeping bag.

[Don Honas]

An idea that people say that they have used in survival situations (unsure if this statement is actually correct, but sound quite plausible). Instead of having to keep a campsite going for a long time, get the option to bury hot coals in the sand that keeps the ground warm and cozy. Then you can place your sleeping bag over it. 

 Advantages: Keeps the heat going over night.

Disadvantages: Does not scare away the wildlife (sleep tight!)