Caravan of Light will be traveling into the Himalayas where it can get chilly. Both Dan and Jim have dealt with living in extremely cold environments. Jim has been in situations where spit freezes before it hits the ground. Here are some of the secrets used for cold weather survival.

Wind Chill Can Kill

One reason outdoor travelers get in trouble is that they don't appreciate the relatively mild temperatures at which hypothermia (high-po-THER-me-a) –– cooling of the body's core temperature –– becomes a hazard. This is because what the thermometer reads is not necessarily the temperature you get. For example, if the air temperature outside is 50 degrees F (10 degrees C) and you have a 30 m.p.h. (48 k.p.h) wind, the adjusted wind chill temperature is 28 degrees F (2 degrees C). A moderately dressed hiker may be comfortable with 50-60 degrees F (10 -15 degrees C) morning temperatures, but may become bitterly cold by mid-afternoon when the wind starts blowing.

Cold Makes You Dumb

When someone's internal temperature starts to drop, so does their intelligence. Victims aren't aware that they are becoming stupid. This leads to carelessness in making decisions. Deciding which trail junction to take or the prudence of skiing down a steep slope may show less forethought. This cold induced dumbness can contribute to getting lost or injured.

Cold Makes You a Klutz

As hypothermia progresses, there is a loss of coordination and balance. The first thing that a warm buddy usually notices is that you are having trouble using your hands.

Cold Makes You Weird

Further cooling causes drunk-like behavior. Victims may act or talk inappropriately and their speech slows down. Prior to unconsciousness, victims can act really strange. There's the story of a cross country skier in the Tahoe area of California who became disoriented. He was later found by search and rescue sheriffs who followed a clothing trail. He took the last of his clothing off to swim across a freezing river. He then walked through the snow for a mile and a half and died wearing only his socks. The reason for this bizarre behavior is that as the man got colder, his internal thermostat, the ability to tell the difference between hot and cold, became so scrambled that even though he was freezing to death, he felt like he was burning up. This can cause a freezing person to remove their clothing.

Dress to Survive

Basic protection from hypothermia is proper clothing The first consideration for proper clothing is material. Cotton is the worst thing to wear in the winter. Wool is better than cotton. The best materials are synthetics like polypropylene (polypropylene materials are used for fleece jackets like you see in backpacking stores).

When dressing for the cold, think onion. Put clothing on in layers. Layered clothing allows the addition or deletion of clothing so you don't soak in your own perspiration. The average person gives off a half quart of water every 24 hours which goes into your clothing. If you are exercising you can sweat even more water into your clothing. When material is wet it moves heat away from your body much faster. For example pure water moves heat away from your body twenty times faster than being in dry air. In this regard, wear clothing that is easy to take on and off so you don't sweat. Pull-over jackets and sweaters are a hassle to remove, especially if you are wearing a pack. Front zippers allow easy removal and ventilation.

Dress Your Head

The most important thing to cover when you are getting cold is your head. Your head is like a chimney. It spews heat into the air. When the temperature is 40 degrees F (4.4 degrees C) out, you can lose half your heat through your head. The reason is because while other areas of your body will shut down blood flow to the surface areas to conserve heat, your brain says, "I don't work unless you keep me at my preferred temperature, so keep that blood and heat coming." Then because your head has little insulation, not much fat on that skull, the heat radiates out into the air. If you are in trouble in cold country, strip off your long underwear and wrap it around your head and neck. A warm head is first priority in cold survival.

• Why would wind make the temperature feel colder?
• Why do you think a cooling brain gets dumber?
• Have you ever heard someone say, "If your feet are cold, put on a hat." Why?