There are several ways to improve your warmth when using a sleeping bag:

  Equipped with a good quality moisture-proof mat, this is very important, often camping people have experience, if the cold 

air from the ground up to the back, the cold is unbearable;

  Conditional words before going to bed to drink a cup of hot drinks, milk and fruit Jane can make the body hot;

  Eat a comfortable meal before bed, especially carbohydrates (starch, sugar);

  Wearing a long thermal underwear and drinking clean socks can be very effective;

  When the sleeping bag is not warm enough, you can wear more clothes or cover clothes and other items on the sleeping 

bag.

  Share a tent with more people;

  Light a gas lamp or stove in the tent if it is safe;

  Fire. So many methods, the key time might as well try.