How to Prevent Hypothermia
To prevent hypothermia, make sure to wear multiple layers of clothing when you get cold, including hats and scarfs to protect your most vulnerable body parts. Additionally, avoid getting wet and change out of wet clothes as soon as possible, since moisture can lower your body temperature. Also, avoid wearing cotton clothes in cold weather as the material easily lets cold air through. If it's particularly windy outside, try to get behind shelter or wear a windbreaker to stop the cold air blowing right through your clothes.
Assess the situation before going out. Whether you're an adventurer planning a backpacking trip or you're just planning to spend a pleasant day outside, take time to look at the weather report and decide how to prepare for your time outdoors. Remember that there's a risk of getting hypothermia even in temperatures that seem relatively warm, since wind and wet weather can cause the body temperature to drop. Know how cold the temperature might get at night. If you're going to be spending the night outside, find out how cold you can expect it to get, and make sure you pack the appropriate clothing and a sleeping bag that will protect you from cold temperatures. There are sleeping bags that are designed for cooler temperatures — make sure your sleeping bag is adequate for the conditions. Have a rescue plan in place. Sometimes things don't go as planned, and you find yourself outside long after you thought you'd be home. Even if you're just going on a day hike, err on the side of safety and bring along a pack with extra layers, a flashlight, and your cell phone in case you need help. Make sure to sign your name in the trail logbook if there is one, so that park rangers know you're still on the trail and will come looking for you when the park closes. If you plan to be out of the range of cellphone coverage, consider bringing a personal locator beacon that can call for help via a satellite network in case of an emergency. Make sure you tell at least two other people where you will be and what time you expect to return. Layer your fabrics to protect sensitive areas. Layering is a very effective way to protect your body from hypothermia. Don't expect just one layer of clothing to be enough protection from cold air. Wear several layers, and bring along extras just in case you need more. The groin, armpits, head, neck, and sides of chest need extra protection. These lose heat more quickly than other parts of the body. Layer your socks and gloves as well, to protect your hands and feet from frostbite. Bring backup layers in case your clothes get wet. If you're packing for an expedition, pack your backup layers in a waterproof plastic bag to keep them dry in case you need them. Follow the "wick, warmth and weather rule" for layering fabrics. Outdoor enthusiasts have found that a certain combination of fabrics provides the best protection from the cold. Layer One: Wear wicking fabric next to your skin. Wicking fabric is designed to keep moisture away from your skin as you sweat, so your body stays dry. Get a long-sleeved undershirt and long johns made from this type of polyester. Layer Two: Wear wool or another warm fabric over the base layer. Wool is the best choice for cold weather, since it breathes but provides excellent insulation and is extremely warm. Layer Three: Wear a waterproof or a windproof layer on top. Determine what type of weather you might encounter and put on one more layer to protect yourself. You might need a windbreaker or rain gear to keep your other layers from getting wet. Don't wear cotton in cold weather. Cotton breathes too much and isn't warm enough to keep you safe from hypothermia. When it gets wet, it can actually leave you worse off, since it's slow to dry and holds moisture against your body. Experts know that cotton is the worst fabric to wear in the cold. Leave your jeans and flannels at home and reach for more effective fabrics to keep you safe in the outdoors. Stay as dry as possible. Moisture is your worst enemy when it comes to protecting yourself from hypothermia. Avoid tromping through wet areas unless you're wearing waterproof shoes and waterproof covers for the bottom of your legs to keep your feet and legs dry. If you're worried about hypothermia, try not to overexert yourself and work up a sweat, since even the moisture you produce while sweating can be dangerous when the temperature drops and your body gets cold again. Note that if you will be home in a few hours, it is okay to work up a sweat. This can increase your metabolism and help you to keep warm in the short-term. The problem is in the long-term (such as if you are staying in the outdoors overnight), because when you stop working so hard your sweat will turn cold and actually drop your body temperature. Take shelter if it starts to rain or snow. If it starts to rain and you have the chance to avoid getting wet, take shelter where you can. Stay inside until the downfall is over if at all possible. After a storm or rainfall, change out of wet clothing and into dry clothing right away. Sometimes it's impossible to avoid getting wet, but that means you need to get dry as soon as possible. Hopefully you brought some backup clothes you can put on to keep dry. Find a break from the wind. Wind can be as dangerous as rain in cold weather, since it blows cold air through your clothes and brings down your body temperature faster than still air. This is especially dangerous if you're also damp from sweat or rain. A good windbreaker will help, but high winds can still penetrate your layers. If things start to get gusty, take shelter, even if it's just in a stand of tall trees. See if you can wait out the windy weather and keep walking when the air is more still. If you want to keep moving, try staying close to the trees or mountainside so that you don't have wind blowing you from both directions. Turn around while you’re still safe. If you feel you are at risk of hypothermia, it's important to turn around right away. Don't let your drive to reach the top of the mountain make you keep going if you're wet and cold. Don't ignore shivering and other early signs of hypothermia. . Look for the symptoms If you believe that you or someone you know has hypothermia, take action right away instead of waiting. Look for the following symptoms of hypothermia: Moderate hypothermia: Shivering Dizziness Hunger Nausea Faster breathing Trouble speaking Slight confusion Lack of coordination Fatigue Increased heart rate Severe hypothermia: Shivering — though as hypothermia worsens, shivering stops Clumsiness or lack of coordination Slurred speech or mumbling Confusion and poor decision-making, such as trying to remove warm clothes Drowsiness or very low energy Lack of concern about one's condition Progressive loss of consciousness Weak pulse Slow, shallow breathing Hypothermia in infants: Bright red skin Low energy A weak cry Take action to help the person get warm. Don't heat the person's body too fast; instead, do it gradually, so that the shock of the heat doesn't cause further damage. Helping the person's body temperature warm to a safe level is the most important step in treating hypothermia. Do whatever it takes to warm the person up, including the following: Get to a warm place. If you don't have access to a heated facility, go to a sheltered spot to wait for help. Make sure it's out of the wind and rain. Remove wet clothing. Take off wet clothes and wrap the person in dry, warm fabrics or clothing. Note that no clothing (or underwear only) is preferable to keeping on wet clothing of any sort. If you or another person in the group has dry clothing they can lend to the person who is cold and potentially hypothermic, now is the time to offer it. Give the person warm beverages. Warm (not hot) tea, soup or even water will help. Note that keeping the beverages warm and not hot is key as you don't want to shock their body with the profound difference in temperature. Do not give the person alcohol, since this will actually drop the person's core body temperature, despite popular belief. Place external heat on the person's body, particularly in the areas of their groin, under their armpits, or on their abdomen (as these areas take up heat the fastest). Hot water bottles or chemical heating pads can do the trick. As a last resort, you can do skin-to-skin contact between you or a group member and the person suffering of hypothermia. This is generally not the most efficient way to re-heat someone, but if for some reason they are the only cold person it can work as a last resort until further help arrives. Make sure you have called for emergency medical help by this point. . Administer CPR if necessary If the person is unconscious or has no pulse, administer CPR. If you aren't familiar with how to administer CPR properly, find someone else who is certified to do so and call emergency services. Once you regain the person's pulse and breathing and CPR is no longer necessary, continue making sure the person is warm and comfortable until help arrives. If you are unable to regain their pulse and/or breathing, continue with CPR until medical help arrives. In you are in a remote location, with no assistance arriving, the general rule is to stop CPR after 30 minutes with no response to the efforts. Seek immediate medical attention no matter what. Get the individual to a health facility as soon as possible. You may call emergency services if you can't reach a hospital. Even if the person warms up and seems fine, it's important to get him or her to a doctor. Hypothermia can cause complications that aren't immediately apparent. The person may also have frostbite or other issues caused by cold exposure. Get medical attention as soon as possible. 
Assess the situation before going out. Know how cold the temperature might get at night. Have a rescue plan in place. Layer your fabrics to protect sensitive areas. Follow the "wick, warmth and weather rule" for layering fabrics. Don't wear cotton in cold weather. Stay as dry as possible. Take shelter if it starts to rain or snow. Find a break from the wind. Turn around while you’re still safe. . Take action to help the person get warm. . Seek immediate medical attention no matter what. 