Winter is full of opportunities for outdoor fun in many forms: Skiing, sledding, skijoring, ice climbing, winter camping, and more. But conditions can grow dangerous quickly when you’re exposed to plummeting temperatures and gusting winds. So, why not take the opportunity to sharpen your winter survival skills before your next outdoor adventure? To that end, the video above offers instructions for starting a fire with ice. What you’ll need is a frozen lake, a sharp knife, warm hands and some dry leaves or wood. A sunny day is also necessary. Find the clearest ice you can find. Carve out a big chunk of it. Then, shape the ice into a disk, and use the warmth of your hands to melt it into a smooth, round lens. Finally, just like you used to use a magnifying glass to set ants on fire, adjust the angle of the ice disk until rays of sunlight shine through it. Focus the sunbeam onto a spot on the ground where you’ve placed some tinder. And voila – fire! If you want something more reliable, especially when it’s cloudy or there’s no clear ice around, gizmag recommends a product called Insta-fire, a gravel-like substance made from volcanic rock, wood pellets and paraffin wax. According to the video below, you just light the substance with a match and it erupts into tall flames that last long enough to cook a camp-meal. Insta-fire, the company claims, can also burn while floating on water or sitting on snow. Now, apparently, there’s no excuse to stay inside, no matter how cold or gusty it is out there.