Hypothermia

HYPOTHERMIA

Dr Mind, Dr Body, Dr Eye 2016

What is hypothermia?

• Hypothermia is defined as a body core temperature less than 35 C.
• Decreased consciousness occurs when the core temperature falls to approximately 32 to 30 C.
• Normal body temperature is 37.2 C

Who is at risk for developing hypothermia?

• WE ALL ARE!!!
• BUT particularly….

1. people under 16 and over 65
2. alcohol use: alcohol makes you feel warm inside, but causes blood vessels to dilate, causing increased heat loss, and can upset thermoregulation
3. medical illnesses that affect sensation in extremities eg feet  and medications
4. dehydration and jetlag

Swimming in cold water

• In cold water, heat is conducted away from the body and transferred to the water.
• Heat is lost very  quickly, 25 to 30 times faster  in water than air.
• Swimming ie activity further increases heat loss (increase by 35-50%)

How long can a person survive in cold water?

Water temp // Exhaustion // Survival
4C-10C // 30 to 60 min // 1 to 3 hrs
10C-15C // 1 to 2 hrs // 1 to 6 hrs
15C-21C // 2 to 7 hrs // 2 to 40hrs

Hypothermia symptoms

• shivering
• clumsiness or lack of co-ordination
• slurred speech or mumbling
• confusion or difficulty thinking
• poor decision making
• lack of concern about one’s condition
• weak pulse
• shallow breathing

USUAL DEMEANOR OF AN ICEBERGER

Swim Failure:

• Swim failure occurs when the arm muscles are cooled to the point they cease working properly
• Children and thin adults are vulnerable
• Another good reason never to swim alone!

Symptoms:

• Hypothermia sneaks up on you, so you probably aren't the best judge of whether or not you are hypothermic.
• Self awareness is your greatest asset.Resisting help and acting irrational or confused are common indicators of hypothermia.
• As your core temperature drops dangerously low, you become semiconscious, then unconscious.
• Low core body temperatures may cause cardiac and respiratory failure

Prevention:

•  Have a hot drink before leaving home
• When leaving home Pack an old jacket/sweater and shoes/sandals and WEAR them. Heat loss occurs in cold air and it is important to be warm before entering the water. 
• Consider if you should swim today, (the café is always a  safe and social option)
• Consider how long you should swim today  
• Consider who you will swim with  (always swim with others ).
• Ask yourself: do I feel well?
• Ask yourself: did I have a big night last night?
• Ask yourself: how did I feel after my last swim? Is it colder? Is it rougher?
• Ask yourself: how many min. can I swim for in winter ?
• Swim within yourself.
• Wear  a jacket/sweater  and shoes on the pier as cold air and wind cause significant heat loss
• If you don’t feel right GET OUT

When trouble strikes

If you suspect you are developing swim failure or hypothermia:

• Tell someone
• Try to stand up if the water is shallow
• Use your legs as they don’t cool, as quickly as your armsand kick to land/platform /board

Signs:

• Severely hypothermic people have icy skin. Extreme lethargy merges with unconsciousness and they might appear dead.
• Since each individual reacts differently, the severity of hypothermia is best measured by taking a core temperature reading using a rectal thermometer

Treating hypothermia

• -Be gentle and limit movements to only those which are necessary
• Get the person indoors to the steam room ASAP and dry them gently with a towel
• Lie the person down in the steam room
• Monitor breathing, pulse and brain eg Ask the person questions eg where are you?what day is it? 
• Share body heat to the chest, warm the core, place  warm arms across the chest
• Provide a warm drink
• DO NOT massage or rub the person
• DO NOT apply direct heat eg a hot shower
• Heat applied to the arms and legs forces cold blood back to the heart and lowers the temperature further.
• DO NOT leave the person alone
• if No pulse or Not breathing then CPR (Try for 2 min to find pulse , breathing)
• CALL AN AMBULANCE
• Don't assume the person is dead, they are only dead when they are warm and dead.

Finally:

• Good luck to us all !!!!!
• Safe winter swimming.
• “Be alert but not alarmed”