Hammocks aren't designed with cold weather camping in mind. Even sleeping bags are helpless against the slightest chill. Grand Trunk's hammock compatible sleeping bag solves this by turning your hammock into a toasty insulated cocoon.
In a normal sleeping bag, the insulation on the back gets squished to oblivion as soon as you get inside, leaving nothing more than a thin piece of fabric protecting your back from the elements. Grand Trunk's hammock compatible bag gets around this by letting you pull your entire hammock through the bag.
Now instead of a sleeping bag pressing against a hammock, you have a hammock inside a sleeping bag. That means the insulation stays lofty so you can stay toasty, even when it's freezing outside. It's one size fits most, so long as hammock apartments don't become the next big thing. It's available for pre-order today for $180. [Grand Trunk via Gearcaster]