this Make tutorial. Another option for smartphones and tablets is a handheld stylus, which is better than a fuzzy finger if you need to do any volume of typing or work in the cold.More snow coming to Midwest, NortheastIn a pinch, you can sometimes use the tip of your nose - - but precision navigation is tricky, and typing is a nightmare.What happens to a chilly phoneSome smartphones list the optimum range of temperatures in their technical specs. For example, when it ' s turned off, theiPhone 5Scan withstand temperatures between - 4° and 113° Fahrenheit. When it ' s turned on, the range is much more narrow. Apple suggests 32° Fahrenheit as the lowest operating ambient temperature. Other phones are rated for much lower temperatures, and some can go as low as - 4° Fahrenheit while in operation. When lithium - ion batteries are exposed to cold temperatures, their performance suffers. When cold, a phone battery can drain faster than normal, or it might say it has ample power remaining and then suddenly go dead. The problems are only temporary and the battery should behave normally when the device is brought back up to warmer temperatures. " In the event that your phone does shut down, do not restart it until you ' re inside and give time for your phone to warm up. Restarting your phone immediately could actually cause more harm to your phone and actually shorten your battery life, " recommends Jeremy Kwaterski ofCPRCell Phone Repair. It ' s not just the battery, says Kwaterski. Smartphones are made up of other delicate electronic parts, like their LCD screens, that can malfunction in extreme temperatures. Freezing temperatures can also make a phone ' s glass surfaces more sensitive to cracks and breaks, especially if there ' s already a flaw or nick in any of the glass. There have beenreports of the glasson the back of the iPhone shattering in extreme cold temperatures. In Finland, where the average high temperature in the winter is 1°C, the governmentConsumer Agencyhas warned citizens that the phones might suffer performance issues in the cold weather.Prevent phone freezeTo keep phones from getting too chilly, don ' t leave them alone for long in frigid places, like a parked car. Stashing them inside pockets closest to your person, where they can absorb some of your body heat, is best. If you do need to leave it behind, turn the phone off instead of just putting it to sleep. Cases also help to keep phones warm. There are even cases especially built to regulate a phone ' s temperature in extreme situations. Still a Kickstarter project, the dapper - lookingSalt Case claims it refracts the heat given off by the device back to the phone to keep it warm in winter weather. It also adds on some additional layers of insulation. The makers say they based the technology on the thermally protective materials NASA developed for its spacecraft. One last tip: If you're depending on a phone to make outgoing calls in case of an emergency -- say, while driving on icy roads -- keep a back-up power source with you.