Bring the right clothes: You will need to bring clothing that can keep you warm during the night as temperatures as get chilly even in summer months. If you’re planning on staying active you will need some outfits that will keep you comfortable but also layers that will help you to regulate your body temperature as you sleep. Layer from head to toe in items that are windproof, waterproof, and comfortable. Don’t forget about gloves in colder months, as frostbite can make a camping trip a lot less fun. Chemical hand warmers can also provide you with a bit of relief during particularly cold times.
Making a Fire: Your fire will become one of the main aspects of your camp site. Be sure to have a proper fire-starter and plenty of wood available to keep your fire burning. You can even bring a hot water bottle that you can heat before bed to bring into the tent. Any amount of heat in your tent can go a very long way.
Bring the right tent/sleeping bag: A quality tent that will hold the heat in is important. You can improve insulation (like an Eskimo) by packing in the snow around the bottom of your tent as well. Packing down snow around you campsite will also prevent snow from making its way into your tent. Sleeping bags that have reflective liners can be especially useful for the winter and for holding the heat in. Consider “head-to-toe” sleeping bags that cover your head and face to prevent heat loss.
Set up a candle in your tent: A towel for scraping away condensation as well as a candle or safe lantern in your tent at night can really make a difference in the temperature inside your tent.
Use Vaseline: Vaseline on any exposed skin for sleeping can be an easy way to prevent frostbite and windburn.