5 Lifesaving Technologies

If y­ou get lost while taking a trek in unfamiliar territory, a GPS receiver will identify your position and allow you to map out a way home.

GPS, which stands for Global Positioning System, consists of three parts: satellites in space, monitoring systems on the Earth and receivers owned by individuals. A GPS will work in all weather conditions, day or night, worldwide.

A GPS receiver provides a user with his or her latitude, longitude, altitude, and time, and it works in the air, on the ground and on the water. Rescuers often use GPS systems in lifesaving missions due to their precise location and timing capabilities [source: Global Positioning System]. With batteries that can last up to 18 hours, a GPS could save you if you lose your way. Some GPS receivers include topographic and trail maps, which could lead you to safety if you're lost in the forest. But even if yours doesn't include a map of the area you're in, it gives you your coordinates. So if you have an up-to-date paper topographic map with you, you should be able to pinpoint your location and plot a way to safety. Most GPS devices include a compass, but it's best you carry a real compass with you as well.

To survive, humans must drink water and eat food. But that water must be clean, which means it should either be filtered or heated up to a boil. And any meat -- for example, a fish you catch the river -- must be cooked. If not, you'll get sick. That's where lifesaving technology No. 4, the camping stove, comes into play.

Sure, you can start up a roaring fire with some matches and logs, but a camping stove is much easier to ignite. And it'll get your water to boiling point and your fish cooked before you'd ever ax enough wood to make a fire.

The two main types of camping stoves are liquid fuel and canister. Canister stoves run on a mix of propane or butane gas. They're generally lightweight, but canisters can't be refilled. Once the fuel runs out, the canister is done. They also don't heat up as quickly in freezing temperatures. Liquid fuel stoves generally burn white gas. The benefit of the liquid fuel stove is that it burns hot even in very cold outdoor temperatures [source: Berger].

If you've ever browsed a store that sells outdoor gear, you've probably heard a salesperso­n use the word "technical" to describe something that doesn't look technical at all -- clothes. But it's not just sales speak. Many of the materials used in outdoor clothing were invented by scientists. And they could save your life. Wearing weather-appropriate clothing is key to survival in the wild. Clothing must keep you warm in extreme cold, keep out water in wet conditions and still be breathable enough to ensure your overall comfort.

Materials like Gore-Tex, eVent and Reflexion are just a few of the many used by outdoor clothing manufacturers to keep people warm and dry out in the wet and cold [source: Acord]. For example, Reflexion, a spin-off from the space program, uses aluminum to reflect heat back to the body. And Gore-Tex repels rain and wet by virtue of the fact that its pores are 20,000 smaller than a drop of water [source: Gore-Tex Technologies].

If you're lost in the wild and your GPS and cell phone don't have a charge, a solar charger could power up your electronic devices and help to lead you to safety. Solar chargers convert the sun's rays to 12V electricity and can be used for a number of electronic devices, including cell phones, GPS receivers, lanterns, handheld radios and other portable electronics.

Solar chargers store energy in internal rechargeable batteries. You can charge the batteries during the day, and then transfer the energy to recharge your electronic devices at night. Most solar chargers are weatherproof, lightweight and pocket-sized, and can even work in low-to-moderate light conditions. These chargers power devices at the same rate as if they were plugged into a wall electrical outlet.

Without a doubt, the most essential element to human food, they can only go without water for a few days [source: Scientific American]. Carrying a water purifier on an outdoor excursion could save your life.

Water filters capture the tiny bugs that live in water so that you don't drink them. If you did, you might wind up with diarrhea, vomiting or much worse. Water filters come with different pore sizes -- the smaller its pores, the more bad stuff the filter is going to catch. A water filter with 0.4 micron pores is recommended for camping because it will filter out bacteria, in addition to larvae, parasitic eggs and protozoa. Some water filters include iodine to also kill viruses in the water.

If you want to go high-tech, there are battery-powered purifiers on the market that use UV rays to kill bacteria. But low-tech filters do the trick without batteries.