how the body works

Awesome sleeping bag...

I bought this bag with the intention on using it on the Appalachian Trail. I was on the Trail March2nd, 2018 and this bag was a life saver. Granted it’s a heavy bag and that is something I was ok with. We had 40mph winds and temperatures below 20 degrees. Before the wind chill was included.
I saw so many hikers beyond cold. Not me...I stayed toasty warm. I’m not a tall guy at 5’10” and weigh about 260 lbs. I was doing a night hike where it was so cold the water bottles froze. I was close to hypothermia from all the sweating I did and this bag saved my bacon. Best bag I’ve ever had.

– Disabled Veteran

He was using an Ultima Thule -20 degree F bag.

Human body | Description, Anatomy, & Facts

Human body, the physical substance of the human organism, composed of living cells and extracellular materials and organized into tissues, organs, and systems

The human body is quite remarkable and it speaks to each of us. I have been thinking that most people do not necessarily listen to it.

My subject is how the human body deals with temperature change and why clothing that has heating capability is potentially dangerous to the normal function as temperature and ambient air temperature change.

The core temperature of the human body is 98.6 degrees F (ALL TEMPERATURE IS REFERRED TO IN FAHRENHEIT [F]).The skin surface temperature is 91 degrees F.

If you are outside and in a relaxed state of motion and the ambient air temperature are 91 degrees F which is the same as your skin surface temperature, you are in a state of equilibrium. Technically you would not have to be wearing any clothing to keep you warm. If you become active your internal temperature will increase from 98.6 to whatever and then the human body via involuntary action will send blood to the skin surface to get rid of the excess heat as well as moisture to leave the body through the pores which will condense on the skin surface to cool it. The moisture will absorb the heat. As the moisture evaporates the skin surface is cooled which causes the blood to stop bring heat to it.

As the temperature decreases the skin surface temperature decreases and now the body needs a covering (insulation) to stop the heat loss that is taking place. If not enough covering (insulation) is employed the body via an involuntary action, shivering takes place.

If the air temperature decreases from 91 degrees F to 75 degrees F not much insulation is required; just a shirt and trouser will suffice. However, as the temperature degreases by 10 degrees F at a time more and more insulation is required to do two things; 1- to trap and retain the heat produced by the body and 2- to protect the body from the lower ambient air temperature. The body all by itself is working to keep its internal core temperature at 98.6 degrees F which means that skin temperature remains at 91 degrees F.

When the ambient air temperature decreases to 40 degrees F it is necessary to cover the human body with approximately one half inch of insulation. When the ambient air temperature reaches 30 degrees F which is 2 degrees below the freezing point the amount of insulation required to keep body temperature normal is approximately one inch of insulation. As the ambient air temperature decreases further the amount of insulation in thickness increases. Generally speaking what the insulation is, is irrelevant for this discussion other than to say the lighter it is with proper density the better off you are, and of course Lamilite has shown itself to be the best choice available now and forever!

The human body therefore is telling you what it needs to maintain itself.

If you introduce an insulating medium such as battery powered heated jackets such as is being introduced into the market place at this time it fools the body and as a result the body reacts to the heat. If the heat source generates enough heat to cause the internal heat to raise above 98.6 degrees F what will the body do, it will send the heated blood to the skin surface and the vapor through the pores which will now condense and coat the skin surface thereby cooling the body. Since there are more than one layer of material covering the body that first layer will now absorb the moisture which will then touch the skin surface causing a chill.If the garment has a thermostat the wearer of the garment may very well turn up the heat further exasperating the situation. When the battery life has expired you will find that the garment is now inadequate to keep the human body at its desired internal temperature of 98.6 degrees F. Depending upon where you are and the ambient air temperature you have chosen to be in will determine how dangerous a situation you have put yourself in. Do you think that the use of electrically heated garments is desirable?

These types of garments and gloves and socks have been around for years. I first encountered them in the late 1960’s. they did not work then and if they did they would have been selling worldwide but that has not been the case. Why, because they do not work!!! There is my proof.