Staying warm whilst hammock camping in cold climates presents a number of challenges but with preparation can be done in comfort.
(see the 'Choosing a Campsite' - winter/ cold climates - page for tips on selecting the best campsite in winter/ cold climates)
The biggest problem you'll face when trying to stay warm is heat loss from underneath due to the compresion of your sleeping bag/ clothes etc. One of the most vital things to have with you is a thermarest/ closed cell pad (ideally 3/4 length) or similar. This is inserted between the two layers of nylon and you lie on top. We recommend using a reflective pad, such as those for car windscreens, these can be found around the perfect size (large enough to cover the your body area but not too large to go in the hammock and also pack up small). Having the reflective side facing up prevents a large amount of radiant heat loss. Avoid using very wide sleeping pads as they tend to buckle and create uncomfortable bulges. Sleeping bags with a central zip (ie. british army ones) are the best to use in hammocks although others are fine.
Use/ wear many layers (thermarest/ reflective pad, sleeping bag/ blanket, jacket and a couple of lightweight jumpers, shirts).
If you have a campfire - warm a couple of stones next to the fire before you go to bed, these can be used as improvised hot water bottles! Another tip that a customer let us know about is using a MSR Dromedary Hydration Bag (similar to a camel pak but tougher and able to hold almost boiling water) as a hot water bottle.