ON THIN ICE!

Sur­viv­ing a plunge into frigid wa­ters

American Survival Guide - - TABLE OF CONTENTS - By Joe Al­ton, M.D.

In the win­ter, north­ern re­gions with lots of wa­ter fea­tures be­come vast fields of ice. Be­cause the short­est dis­tance be­tween two points is a straight line, you might be tempted to cross that frozen lake rather than go around it. That’s fine if the ice is thick; but, if it’s not, there’s a risk of fall­ing through the ice. If so, you’ll be in ex­tremely cold wa­ter (and ex­tremely big trou­ble). How thick must the ice be to sus­tain the av­er­age per­son’s weight? At least 4 inches for any rea­son­able ac­tiv­ity such as walk­ing or cross-coun­try ski­ing. On a snow­mo­bile or all-ter­rain ve­hi­cle, at least 5 to 6 inches would be re­quired. Al­ways stay off ice that’s thought to be 3 inches thick or less, es­pe­cially on warmer days, when ice might be thaw­ing. Note that sea ice is weaker and re­quires a greater thick­ness to sup­port the same weight as fresh-wa­ter ice.

HOW YOUR BODY LOSES HEAT

Your body has var­i­ous meth­ods it uses to keep its in­ter­nal core tem­per­a­ture at ap­pro­pri­ate lev­els. The “body core“is com­posed of the ma­jor in­ter­nal or­gan sys­tems that are nec­es­sary to main­tain life, such as your brain, heart, liver and oth­ers. A drop in the body’s core tem­per­a­ture of just 4 de­grees (F) be­low nor­mal might cause ill ef­fects due to the cold—a con­di­tion known as “hy­pother­mia.” In cold weather, your blood ves­sels con­strict in­vol­un­tar­ily to con­serve heat. Mus­cles “shiver” as a method of heat pro­duc­tion. As well, you can vol­un­tar­ily in­crease heat with ex­er­tion; that’s why it’s rec­om­mended to “keep mov­ing” in cold en­vi­ron­ments. When the body is ex­posed to se­vere cold, as in the case of a fall through the ice, it’s dif­fi­cult to main­tain a nor­mal core tem­per­a­ture. Cold wa­ter, be­cause it is denser than air, re­moves heat from the body via a process called “con­duc­tion.” Wa­ter “con­ducts” heat away from the body much faster (some say 32 times faster!) than air does. The higher the per­cent­age of body sur­face area that is sub­merged, the faster it loses heat.

THE "1-10-1 PRIN­CI­PLE"

The U.S. Coast Guard 1-10-1 Prin­ci­ple gives us a sober­ing glimpse re­gard­ing your prospects if you have to spend time in icy cold wa­ter: • 1 minute—you have one minute to gain con­trol of your breath­ing. • 10 min­utes—you have 10 min­utes to re­al­is­ti­cally help in your own res­cue. Cold tem­per­a­tures will cause loss of sen­sa­tion and mo­tor con­trol of mus­cles, lead­ing to what is known as “swim fail­ure.” Af­ter 10 min­utes, vic­tims without a life jacket will drown. • 1 hour—you have one hour, more or less, be­fore hy­pother­mia ren­ders you un­con­scious. One ma­jor fac­tor is, of course, the wa­ter tem­per­a­ture. An­other vari­able in a per­son’s sur­vival is the amount of body fat the vic­tim has. Body fat helps con­serve heat and might in­crease the time in­ter­val be­fore the pa­tient be­comes hy­pother­mic. Take the ex­am­ple of pas­sen­gers on the Ti­tanic. Un­less there was an avail­able seat on a lifeboat, they ended up in 40 de­gree (F) wa­ter. Within 10 min­utes, they were likely un­able to help them­selves in any sig­nif­i­cant way.

THE TORSO RE­FLEX

When a per­son falls through the ice, they ex­pe­ri­ence a phys­i­o­log­i­cal re­ac­tion known as the “torso re­flex,” some­times called the “in­hala­tion re­sponse.” When the body is sud­denly im­mersed in tem­per­a­tures be­low 70 de­grees (F), the torso re­flex causes the vic­tim to in­vol­un­tar­ily gasp. This re­ac­tion is meant to in­crease oxy­gen in­take into the lungs and in­crease me­tab­o­lism to build in­ter­nal warmth. When the head is be­low the sur­face, how­ever, the sud­den urge to breathe causes wa­ter to be in­haled in­stead of air. When this hap­pens, air­ways can go into spasm, caus­ing the dis­ori­ented vic­tim to panic. Cou­pled with a mas­sive re­lease of adren­a­line, as well as sud­den

AL­WAYS STAY OFF ICE THAT’S THOUGHT TO BE 3 INCHES THICK OR LESS, ES­PE­CIALLY ON WARMER DAYS, WHEN ICE MIGHT BE THAW­ING. NOTE THAT SEA ICE IS WEAKER AND RE­QUIRES A GREATER THICK­NESS TO SUP­PORT THE SAME WEIGHT AS FRESH­WA­TER ICE.

changes in heart rate and blood pres­sure, many lose the abil­ity to per­form the ac­tions that might save their lives. Although some as­pect of the torso re­flex oc­curs in just about ev­ery­one who is im­mersed in cold wa­ter, the re­sponse seems to be vari­able among in­di­vid­u­als. Im­mer­sions in­volv­ing the face seem to be the most se­vere. Some out­doors­men who reg­u­larly kayak in north­ern wa­ters ap­pear to be af­fected less often. This might be due to ac­cli­ma­tion to the cold or ex­pe­ri­ence with mul­ti­ple “dunk­ings” over time.

FALL­ING THROUGH THE ICE

Cer­tainly, a fall through lake ice can be life-threat­en­ing, but your chances of sur­viv­ing are much greater if you know what to do. If you can keep it to­gether men­tally, a few sim­ple steps might save your life. Stay calm: The shock of a sud­den im­mer­sion in cold wa­ter makes it dif­fi­cult to think, as well as breathe. In some cir­cum­stances, you might re­al­ize the ice is go­ing to break un­der your weight. Faced with this, it’s im­por­tant to brace your­self and try not to in­hale wa­ter if you go un­der. This will be dif­fi­cult, but it is more pos­si­ble if you have some warn­ing that a dunk­ing is im­mi­nent.

WHEN THE BODY IS EX­POSED TO SE­VERE COLD, AS IN THE CASE OF A FALL THROUGH THE ICE, IT’S DIF­FI­CULT TO MAIN­TAIN A NOR­MAL CORE TEM­PER­A­TURE ... THE HIGHER THE PER­CENT­AGE OF BODY SUR­FACE AREA THAT IS SUB­MERGED, THE FASTER IT LOSES HEAT.

Torso re­flex might be pre­vented by cov­er­ing your mouth and nose with your hands be­fore get­ting im­mersed. If you can es­tab­lish the “seal” as you en­ter the wa­ter, you’ll have a bet­ter chance of not drown­ing. This pro­ce­dure should be taught to ev­ery­one spend­ing time in prox­im­ity to cold wa­ter and should be main­tained un­til the head is above the sur­face. Make ev­ery ef­fort to keep calm. You have a few min­utes to get out be­fore you suc­cumb to the ef­fects of the cold. Panic is your en­emy. Get your head out of the wa­ter: This is best ac­com­plished by breath­ing in and bend­ing back­ward as soon as you get your head out of the wa­ter. If there are oth­ers nearby, shout that you’re

in need of emer­gency aid.

Get rid of heavy ob­jects that weigh you down: The more you weigh, the harder it will be to get your body out of the wa­ter. Tread wa­ter and turn: Tread­ing wa­ter by kick­ing with your legs will help raise you farther out of the wa­ter. Quickly turn your body in the di­rec­tion you came from—you know the ice was strong enough to hold you there. Try to lift up out of the ice: Place your arms on the ice and spread them widely apart in front of you. Kick with your feet to give you some for­ward mo­men­tum and try to get more of your body hor­i­zon­tal and out of the wa­ter. Lift a leg onto the ice, and then lift and roll out onto the firmer sur­face. Do not stand up: Keep rolling in the di­rec­tion that you were walk­ing be­fore you fell through. This will spread your weight out in­stead of con­cen­trat­ing it on your feet. Then, crawl away un­til you’re sure you’re safe. Get warm as soon as pos­si­ble: You’re out of the wa­ter—but you’re not out of the woods! Get to a warm place if pos­si­ble. Hy­pother­mia is highly likely, and soak­ing-wet cloth­ing isn’t help­ing. Hav­ing spare clothes or a blan­ket avail­able in a hik­ing part­ner’s back­pack is an im­por­tant con­sid­er­a­tion. So is hav­ing a way (or two or three) to start a fire if no heat source is at hand. Chang­ing into dry cloth­ing should be done im­me­di­ately and be­fore start­ing a fire: Ex­ter­nal heat sources aren’t very ef­fec­tive in pen­e­trat­ing wet cloth­ing. It’s pos­si­ble that you might have to change out­doors. If so, stay out

A DROP IN THE BODY’S CORE TEM­PER­A­TURE OF JUST 4 DE­GREES (F) BE­LOW NOR­MAL MIGHT CAUSE ILL EF­FECTS DUE TO THE COLD—A CON­DI­TION KNOWN AS “HY­POTHER­MIA.”

of the wind by stand­ing be­hind a large tree or some other bar­rier. Once you have ac­cess to a heat source, get close enough to feel the warmth and bring your knees to your chest with your legs tightly to­gether. This will help con­serve body heat. Have oth­ers share body heat with you if pos­si­ble.

PRE­VEN­TION

Of course, an ounce of pre­ven­tion is worth a pound of cure. Avoid sit­u­a­tions where vis­i­bil­ity might be re­duced, such as travers­ing frozen lakes at night or dur­ing heavy snows. Even in con­di­tions that af­ford good vi­sion, stay clear of un­fa­mil­iar ter­rain. Any back­coun­try travel plans should be shared with oth­ers who can send for help if you don’t reach your des­ti­na­tion or if your re­turn is over­due. This is good pol­icy in any sea­son. Once you are on the ice, see if there are any cracks or ab­nor­mal sur­faces. The strength of the ice is not the same ev­ery­where on the same body of wa­ter. Be­ware of flow­ing wa­ter at the

edges, springs un­der­neath and ice that has thawed and re­frozen. Although by no means can ice safety be guar­an­teed on sight alone, the col­ors of the ice might give you a clue: Blue/clear Ice: This ice is thought to be the high­est den­sity, but it is only safe if it is 4 or more inches thick. White/opaque Ice: Snow freezes and forms a sec­ond layer above the main body of ice. This ice is often weak due to air pock­ets be­tween lay­ers. Snow can also act as an in­su­la­tor and warm up the ice, thus weak­en­ing it. Mot­tled Ice: This ice is un­safe due to thaw­ing and de­te­ri­o­rat­ing at the cen­ter and base. Gray or Black Ice: This is low-den­sity, melt­ing ice. It is un­safe.

MAKE EV­ERY EF­FORT TO KEEP CALM. YOU HAVE A FEW MIN­UTES TO GET OUT BE­FORE YOU SUC­CUMB TO THE EF­FECTS OF THE COLD. PANIC IS YOUR EN­EMY.

h Ice should be 8 to 10 inches thick for a car to safely drive on it.

i Right: Think twice be­fore travers­ing a frozen lake, be­cause that short­cut might be dan­ger­ous.

i Right: Mot­tled ice is un­safe to travel on due to thaw­ing and de­te­ri­o­rat­ing at the cen­ter and base.

h Left: Travel in the cold can in­duce hy­pother­mia.

h Be­low, left: Once out of the wa­ter, work to get warm im­me­di­ately. h Be­low, right: A vic­tim can eas­ily get dis­ori­ented and might not sur­vive a fall through the ice.

h Above: Af­ter an im­mer­sion, change out of wet clothes as quickly as pos­si­ble and drink some­thing warm.

i Right: Full body im­mer­sion in cold wa­ter leads to sud­den and pos­si­bly dan­ger­ous ef­fects. While some peo­ple do it recre­ation­ally, they should never do this alone. i Bot­tom: A part­ner with a length of rope can save your life.

h Left: A cap­sized raft could mean death in cold wa­ters. h Above: Trans­port the vic­tim out of the cold as quickly as pos­si­ble af­ter their ex­po­sure to icy wa­ter.

Newspapers in English

Newspapers from USA

© PressReader. All rights reserved.