Tuesday, November 15, 2011

National Hunger and Homeless Awareness Week

Just a short post today to recognize that it is nation hunger and homeless awareness week.  There are tons of people less fortunate than us and they deserve a helping hand every now and then.  I encourage all of you to Donate to the nation coalition for the homeless, or go find a homeless person and give them something.  It doesn't need to be money; give them some food and a blanket, maybe some clean socks.  I'm sure they will appreciate anything you have to offer.  Just remember that while you are reading this, there are people freezing and starving to death, possible on the same block as you.

"As much as we need a prosperous economy, we also need a prosperity of kindness and decency."
-Caroline Kennedy

Friday, November 11, 2011

Cold Weather Survival Techniques

Okay everyone it's time for a little science lesson.  It's getting colder out so I feel obligated to school you a little bit on cold weather survival techniques.  A few things I want you all to learn about:

Skin cover + wind chill
Heat Capacity
Energy + muscle physiology

I suck at intro so I’m going to get right to it.  Skin cover is fairly straight forward concept.  If it is cold out, you don’t want to have you skin exposed to the environment.  What you want to think about though, is what kind of skin cover you are getting.  One of the functions of clothing is to trap a bubble of heat between and the outside world.  Your body is constantly giving off heat through your skin.  Your clothing is what determines whether that heat is lost or salvaged.  I was once told that if you feet get cold, cover you head.  Because there is so much blood pumped your head to feed your brain, you lose up to 75% of you heat through your head.  In cold environments, the cold air will cool the temperature of the blood in your head, and then that cold blood is pumped to the rest of your body.  So even if a part of your body is thoroughly insulated, its can still get cold.  If you have a good insulating layer on around your head and core, you can maintain homeostasis in extremely cold environments.  However, wind chill can ruin that for you. For you noobs, wind chill is the idea that the faster the wind is, the colder the air will feel on your skin.  So depending on the wind, if it is 20 degrees out it could potentially feel like 0 degrees outside.

Before we get into that lets have a quick lesson in heat capacity.  Basically, heat capacity is a quantitative measure of how well an object or substance retains heat.  The two important examples here are air and water.  Water has a much higher heat capacity than air.  That means that it is takes much more thermal energy to raise the temperate of water than it does to raise that of air.  The reason it is so important to stay dry when it is cold out is because water will steal a bunch of heat from your body to acclimate itself to your temperature.   The same thing happens with cold air, but it just not as bad.  However, with wind chill there is a much higher volume of air hitting your body.  This means that you are stripped of your thermal energy much faster as more and more cold air hits you.  If you have any exposed skin while there is harsh wind chill, the cold air can literally strip all the heat from your skin until you get frost bite. 

Frost bite is when the temperature of your skin goes below the freezing temperature of water.  This causes the water in your skin cells to freeze and crystallize into sharp fragments of ice.  Frost bite “burns” because these sharp fragments of ice rupture the your skin cell walls and kill the cells, similarly to how the skin cell ruptures from the cell water boiling can causing the cell to burst open during a burn.  The most important thing I can tell you about frost bite is to never ever rub it.  If you rub it, you will feel warmer, but what is actually happening is you are rubbing all those tiny fragments of ice into more skin like sandpaper, and it will literally turn your flesh into a dead hamburger meat like substance.  The second thing I should tell you is not to warm up and short term, if you are only going to be exposed again.  If you get frost bite and then warm up, the ice will liquefy back to its normal state, which is good.  But, if your skin warms up and then gets cold again before healing, the ice crystal will reform ever worse not that cellular walls are breached, and the simple freezing and unfreeze will have the same effect as rubbing the ice crystal into your skin.  Dead skin and infections.  Here is a picture of some very mild frostbite, notice how it looks like a burn.  Serious frostbite will result in black skin.

Hypothermia is when your body’s core temperature drops below the required temperature for adequate metabolism.  Metabolism is a set of chemical reactions that breaks down food into utilizable nutrients to feed the body.  Without metabolism, you body can’t functions.  Think of metabolism as your car engine.  Even if you have gas (food in your stomach); without an engine the car won’t run.  So, when your core temperature cools down, you body panics and goes into overdrive.  You body will begin to shiver.  When your muscles contract they produce heat.  This is one of the reason your sweat when you work out.  Shivering is just a fancy term to describe rapid muscle contraction for the sole purpose of producing heat to warm the body.  Shivering is an extremely inefficient use of resources, because its wastes a ton of energy.  Regardless though, wasting energy is better than dying, so your body will do it to keep you alive.   I’m telling you all this because it’s likely that you will find yourself in a situation where you are unable to provide your body with adequate shelter and insulation from the cold.  If you know ahead of time that this will have, pack as many calories as you can into your body so there are plenty of nutrients for your body to waste.  This is kind of a last ditch effort to stay warm, but it could save your life to have enough food in your to shiver through the night. 

Well that’s all for now guys.  Take this knowledge that I gained in college and keep yourselves warm.