เลขเด็ดเเนวทางล่าง เลขคนใน นกตาทิพย์ เสือน้อย 1/6/62
Most modern sleeping bags are tested in very cold conditions and have been scientifically designed to withstand the rigours of mountaineering. It is the scientific advances over the last few years that have made it possible for climbers, campers and thrill seekers to stay alive in remote locations at sub zero temperatures.
from: http://ezinearticles.com/?3-Sleeping-Bag-Innovations-That-Stop-You-From-Freezing-to-Death&id=4627848
