Two months without food?

It's been awhile since I've written about the Rule of 3's in this blog:

An average person may die after
Three minutes without air
Three hours without shelter (in extreme heat/cold)
Three days without water
Three weeks without food

http://perpetualpreparedness.blogspot.com/2010/04/return-of-rule-of-threes.html
http://perpetualpreparedness.blogspot.com/2008/07/rule-of-threes.html

Keep in mind that the rule is about the average person and average events. There are exceptions.

Some drowning victims have survived for 8 to 10 minutes with no brain damage in icy cold waters that send the body into instant shutdown with hypothermia. A similar thing happened to a man in Sweden who was trapped in his car for nearly two months before being discovered.

His doctor explained that besides eating snow, the man probably survived by going into a dormant-like state,

"A bit like a bear that hibernates. Humans can do that. He probably had a body temperature of around 31 degrees (Celsius) which the body adjusted to. Due to the low temperature, not much energy was used up." 

The car itself, covered in snow, acted as an igloo, so the man did not freeze to death.

Bottom Line

While researching this blog I saw references to a Rule of 4s
Four minutes without air
Four hours without shelter (in extreme heat or cold)
Four days without water
Four weeks without food

This might be more accurate for people in excellent health and fitness but I'll stick with the Rule of 3's for the average Joe.

How long does it take to get Frostbite?

How long does it take to get frostbite? Sounds like an easy question but I find many different answers on the Internet (including one tough old New Englander who answers, "never", with proper clothing). Part of the confusion lies in the definition of "Wind Chill". See http://perpetualpreparedness.blogspot.com/2010/01/wind-chill.html for details. There have been two changes.

1st:  In Nov. 2001 the wind chill values were changed based upon a new equations, see http://www.crh.noaa.gov/ddc/?n=windchill. Whereas 15°F used to be extreme cold in 20mph wind, now it's "safe" at all wind speeds and never drops below -11 wind chill.

2nd: Some revised charts appear to use the new wind chill values but kept the color bands the same for exposure times. See this NOAA chart from 2010 which still has 15°F freezing within 5 minutes with strong wind. http://www.srh.noaa.gov/jetstream//global/chill.htm

A new NOAA chart from 2011 (pictured above) updates the color zones. http://antarcticfudgesicles.wordpress.com/afsa-student-page/how-long-does-it-take-to-get-frostbite/ The exposure time colors don't exactly match the wind chill numbers anymore (for instance -40 wind chill is in two different color zones).
Wind chill of -20°F to -35°F (approx) Frostbite in 30 minutes for exposed face, at night.
Wind chill of -35°F to -50°F (approx) Frostbite in 10 minutes.

There used to be a -30-30-30 rule that -30°F with a 30 mph wind could freeze skin solid in 30 seconds. Under the new chart it's -30 & 30mph & 5 minutes for frostbite.

Bottom Line
So what happened to the NOAA charts? During the fall of 2000, the Office of the Federal Coordinator for Meteorological Services and Supporting Research (OFCM) organized a joint U.S.–Canadian government-sponsored action group to develop, test and implement a new Wind Chill Temperature Index. Human trials were done in Toronto, Canada with 12 volunteers in chilled wind tunnels with thermal transducers stuck to their face while walking on a 3mph treadmill. Brrrrr.

So the new chart is based on solid human evidence of facial skin instead of mathematical modes and time to freeze bottles of water.  See http://www.nws.noaa.gov/om/windchill/images/wind-chill-brochure.pdf for more information.

Would you take shelter inside an animal?

Sleeping bag

"This may smell bad, kid, but it'll keep you warm until I get the shelter up... Ugh. And I thought they smelled bad on the outside."
-Han Solo, The Empire Strike Back

Continuing the topic of off-beat ways to stay warm, StraightDope.com was recently asked, "What’s the best animal to slice open and crawl inside to stay warm?" In Star Wars, The Empire Strikes Back, Luke is put inside a freshly killed tauntaun to avoid freezing on the ice planet Hoth. Would this work in real life?

Cecil Adams first offers some silly answers,

"taking shelter inside dead animals can’t really be considered an affordable housing option ... Many large warm-blooded critters would do, such as a bear, water buffalo, or rhinoceros. Historically, however, the emergency refuge of choice was a horse. ... Slice one open even in case of dire necessity and you’re likely to hear from one PO’d little girl or dressage buff. Cows are less of an issue, but you still take the chance of having PETA come over and picket your house."

Then he gets serious,

"I could find only one case where someone had actually climbed into an animal to survive the cold as opposed to trying to get on TV, namely an intrepid pioneer priest named Father Goiffon. [He became lost in North Dakota in a snowy November]  When his horse finally died, the enterprising priest cut open its belly and crawled inside the carcass. He was mostly successful — his equine sleeping bag saved his life, but he lost his leg due to frostbite."

Bottom Line

Cecil concludes with an example that also sheds some light on my question from a few days ago, when does cold weather became too dangerous to endure?

How much time would sheltering in a deceased animal buy you? Assuming a bitterly cold day (9 degrees Fahrenheit), a stiff wind (12 miles per hour) [about -5 wind chill], and a 500-kilogram cow with half its insides scooped out, and factoring in the heat produced by the resident human, my assistant Una estimates the cow’s body would lose about 3 degrees per hour. She concludes you’d have right around 15 hours, best case, before hypothermia set in.

Money to Burn? - Literally

"Gotta use your brain, it's the most important part of your equipment."
~Kevin Andrews and Warren Miller, Extreme Skiing

Here's an odd story about keeping warm. A 66-year-old man was snowshoeing on Mt. Rainier in Washington state when he slipped down a slope and became separated from his group. During the two freezing days it took to find him and rescue him, he kept warm by running in palace and burning things. He had a package of fire starters for he began by burning all the leaves he could find. When those ran out he burned his socks. Then he started burning his cash. Just the small bills, $1s and $5s - nothing crazy like $20s. It worked and he's fine now.

Bottom Line

The story reports that Mr Kim has been "snowshoeing for a decade, was well equipped for a day trip but didn't have overnight gear."  When hiking or snowshoeing in wilderness, always pack overnight gear. You never know when an accident or weather will trap you outside.

Staying warm when the heat is out

Winter is not a season, it's an occupation.
~Sinclair Lewis

Here are some ideas for staying warm when your house/apt. heat is not working:

Dress warmly! Wear a hat and socks indoors and even in bed! Dress in many layers from head to fingers to toes. Put on a winter coat or make your own by stuffing your clothing with crumbled up newspapers, paper towels or other insulating materials.

Snuggle and share body heat with family and pets.

Heat rises so stay upstairs.
Plug any air gaps around windows and doors.

Close doors to unused rooms. This will reduce drafts and retain what little heat your bodies give off.

Cover floors with a carpet or blanket.

Vigorous exercise warms the body and moves heat to fingers and toes.

When sitting still wrap yourself in a blanket or thick bathrobe.

Bottom Line

Know your limits to avoid frost bite and hypothermia! Sometimes the best thing to do is leave a cold house and find a shelter with heat.

Most fireplaces do a poor job of heating a room. NEVER leave a fire unattended or burning while you sleep and do not dispose of fireplace ashes near your house. Space heaters and candles are a fire risk when used near flammable items. Gas powered heaters are also a carbon monoxide risk when there is no ventilation.

NEVER use a power generator indoors. While TV news emphasizes tornados, hurricanes and earthquakes, the real killers in nature are heat and cold. Globally there are more deaths from extreme cold than from extreme storms. Freezing to death is very real, especially for senior citizens and infants. Freezing cold can also inspire desperate measures to stay warm which lead to death by house fire or carbon monoxide poisoning.

When is it too cold to stay home?

How low can you go?

- lyrics to "Limbo Rock"

I was asked yesterday, "If a house is without heat, at what temperature does it become unsafe to stay?" Or to put it another way, "At what temperature should one evacuate a home?"

I've searched the Internet and found nothing useful so I'm hoping that some reader can provide an answer. One site said that temperatures below 70 F can be dangerous (to the elderly perhaps???) if no protection is taken (like a sweater?). That seems way too extreme. At my home in winter, I'm lucky if I can convince the wife to set the thermostat up to 63 F. It's often 60 by day and 55 at night. For me 63 F is tolerable with layered clothing but below that my fingers become chilled.

When we lost power with the Halloween Nor'Easter we put on coats and hats and did OK for awhile as the temperature fell over several days. At 40 F we were becoming concerned but then the power was restored.

A site on wind chill said that -20 F was "dangerous". It may be true that even brief exposure to -20 F is dangerous but what about prolonged exposure? Someplace else warned about 30 F and below.  At that temperature you must to take active precautions to prevent your extremities from freezing with frostbite but it is survivable. When I attended an igloo making class the instructor warned against overheating the inside of the igloo. If the temperature got above 32 F the igloo would melt from the inside-out. So igloo dwellers must cope with the 30-32 F range.

Bottom Line

There might not be one simple answer. Temperature tolerance does depend on age and health and body fat. Still it would be nice to know how low is safe?

Treating Frostbite

I'm dreaming of a white Christmas
Just like the ones I used to know
-White Christmas by Irving Berlin

While we may have wished for a White Christmas, too much exposure to cold and snow can be dangerous. Your body is 60% water and the water in your skin can freeze to ice. This is called frostbite.

Think about water in a ice cube tray. When it freezes, the ice cubes are larger than the water poured in. (The expansion of ice is why ice floats in water.) When ice crystals form in skin or muscle cells the ice expansion and sharp icy prongs bursts the cells and kills them. If the damage is small, it may be painful, but recoverable. However extensive freezing and cell death may result in gangrene and the loss of fingers, toes, ears, nose, etc.

Frostbite usually develops below -12°C (10°F), but may occur at a temperatures near freezing (0°C/32°F) when high winds and/or dampness chills the body faster than your blood can keep it warm. Hands, feet, noses, and ears are the most likely body parts to be affected.

Avoid frostbite by staying out of extreme cold. If you must go out (or become lost, stranded in extreme cold) cover all extremities - winter boots for the feet, gloves for the hands, a hat or earmuffs for the the ears and a mask or scarf for the face. Mittens are more effective than gloves for warming your hands since the fingers can share body heat instead of isolated on their own. Avoid caffeinated beverages (like coffee) as they constrict blood vessels and prevent warming of your extremities. Alcohol should also be avoided since it reduces shivering, which is one way of keeping warm. Cigarette smokers may be at higer risk with reduced blood flow to hands and feet.

Wiggle your fingers and toes frequently to increase blood flow to these areas. Keep your feet and hands dry. If you begin to loose feeling in your fingers and toes, or they begin to tingle, or feel painful, go inside and warm up.

Signs and symptoms of frostbite include:

• A "pins and needles" sensation, followed by numbness
• Hard, pale, cold skin

Different Degrees of Frostbite

• First degree: ice crystals forming on top of your skin
• Second degree: your skin begins to feel warm, even though it is not yet defrosted.
• Third degree: your skin turns red, pale, or white.
• Fourth degree: pain lasts for more than a few hours, and you may see dark blue or black areas under the skin. See a doctor immediately if these symptoms arise. Gangrene is a real threat.

Bottom Line

If your skin is blue or gray, very swollen, blistered, or feels hard and numb even under the surface, go to a hospital immediately.  Otherwise get indoors or to a warm shelter ASAP. Take off any constricting jewelry (flesh may expand and rings are sometimes cut off a swollen finger). Take off wet clothing. Never rub or massage frostbitten skin, but do use your armpits or the body heat of a warm companion.

If possible, immerse the affected area of your body in warm -- NOT HOT -- water, or apply warm cloths to affected areas of your ears, nose, or cheeks for 20-30 minutes. Try to move the area of your body that is affected as little as possible to decrease doing additional damage.

You should not use hot water or a heating pad, heat lamp, hair dryer, or the heat from a stove, fireplace, or radiator to warm yourself. This because your frostbitten area may be numb and you won't be able to feel if you're overdoing the heat and burning yourself.

As you warm up your frostbitten skin will become red and swollen, and you'll feel like it's on fire. You may develop blisters. Don't break the blisters. It could cause scarring.

Wind Chill

"I've got to go home - Oh, baby, you'll freeze out there
Say, lend me your coat - It's up to your knees out there"
- song lyrics from Baby It's Cold Outside

Slate.com recently published an article, "It's time to get rid of a meaningless number", that is opposed to the idea of "Wind Chill factor". The columnist believes that "no amount of tweaking will make wind chill more comprehensible."

Let's start at the beginning. In 1945 two Antarctic explorers, Paul Siple and Charles Passel, realized that a bottle of water would freeze faster on a windy day than on a calm day. This is because the wind is more efficient at carrying away the heat in the water. They carefully recorded wind speed and freezing times to create a chart and formula uniting wind and temperature. So given 5 F and a wind speed of X, you could calculate that a bottle would freeze in the same amount of time as a calm day of -40 F.

The concept of wind chill was first used by Canadian Weather men in the 1970s. The Siple-Passel formula was used for 30 years before two researchers, Randall Osczevski in Canada and Maurice Bluestein in the United States, decided to retest the numbers. They found that the Siple-Passel formula was too extreme in its predictions. So instead of -40F above the same 5F and wind would feel more like -19F.

So this is confusion #1 - the system of wind chill was changed at the turn of the century.

Confusion #2 - If it's a windy day at 35F, the wind chill might "feel like" 20F but no bottle of water (or anything else) is going to freeze. The coldest anything can get in this example is 35F - safely above freezing. All wind chill does is tell you how quickly you'll cool down to the outdoor temperature - not how cold you will become. Wind does not make things colder than the air temperature - it just makes them as cold, faster.

Confusion #3 - Your results may vary. The actual rate at which your body cools will depend upon the clouds & sun, how much skin you have exposed, how insulating your coat is, how exposed you are to the wind, and so on. The modern Wind Chill model is based upon people who are 5 feet tall, somewhat portly, and walk at an even clip directly into the wind.

Bottom Line

Wind Chill is useful as a reminder about the dangers of a cold wind but keep in mind the limitations mentioned above. Also remember that wet clothes draw out heat and will cool you down faster than dry clothes. Stay dry and out of the wind.

Check out one of my early blogs for more details on Hypothermia.

Hypothermia

"Never such a blizzard before"
- from the song Baby it's cold outside

Hypothermia describes the rapid, progressive mental and physical collapse caused by the chilling of the inner core of the human body. It is the number one killer of outdoor recreationalists who simply can't believe that temperatures between 30 and 50 degrees can be dangerous. When dry and covered you might survive 30 degree air. But swimming in 50 degree water can be deadly and when your clothes are wet in fifty degrees air, the cold water running down your neck and legs quickly robs body heat. A blowing wind will go through and under wet clothes, evaporating water on your skin, causing a refrigeration effect.

I'm quite impressed by the site http://www.adventuresportsonline.com/skihypo.htm which provided the hypothermia information above. It also charts comparing water temperature to survival times, signs of hypothermia, what to do, and more.

From eMedicineHealth I learned that Hypothermia has been a military problem ever since Hannibal lost nearly half of his troops while crossing the Pyrenees Alps in 218 B.C. It has continued to plague military campaigns through both world wars and the Korean War.

Bottom Line

Uncontrollable or violent shivering is a warning sign of early stage hypothermia. Shivering can double heat generation for a few hours. But eventually fatigue sets in, and the body exhausts its fuel stores. As your core body temperature drops, cold reaches the brain depriving you of good judgement and reasoning power. You will not realize this is happening. You will lose control of your hands, then your body, and eventually die.

Seek help immediately while you still have the energy, the muscle coordination, and the common sense to reach help. However if you're lost don't wander at random hoping to be rescued; seek shelter instead. Once sheltered, take off wet clothes and replace with dry if available. Refuel your body with food and water. Do NOT consume alcohol, caffeine or tobacco. Build a fire. Get inside a sleeping bag if available. If you're not alone, huddle with others to share body heat.

For more details see also the Outdoor Action Guide.

The Importance of Shelter

All architecture is shelter, all great architecture is the design of space that contains, cuddles, exalts, or stimulates the persons in that space. -Philip Johnson

Unless you're an expert breath holder, most people have no problem accepting the 1st Survival Rule of Three - find air within 3 minutes. However I've seen lots of misunderstanding over the second Rule of Three - find shelter within 3 hours. One commenter on a different blog pointed out that he frequently spends more than 3 hours at the beach with no difficulty.

However, the beach goer did have shelter - if the sun became too hot he could retire to his car or his house. When far from civilization, you should establish a shelter within the first few hours to keep dry or become dry, to stay out of the wind, and to find warmth or shade BEFORE weather conditions turn fatal. For hikers, shelter may be a tent they carry on their backs. It could be your car, a cave, a cabin, etc. Here are some links on creating your own emergency shelter:

http://www.abc-of-hiking.com/hiking-tents/outdoor-shelters.asp
http://en.wikibooks.org/wiki/Outdoor_Survival/Shelter
http://www.essortment.com/all/howdoyoumake_rkdt.htm
http://outdoorsurvival.org/quick-emergency-shelter

Bottom Line

Provide a shelter BEFORE you need it. While a shelter may be a place to keep "your stuff" (George Carlin) its real value is to maintain your body temperature under adverse conditions - too much heat leads to heat stroke, too little heat causes hypothermia.

Tomorrow's topic will cover hypothermia.