It has been cold. Very cold. Ed and Kurt have been working in less than ideal weather, for a while now. The temperature is not allowing glue to set, which is requiring Kurt to complete building the windows over at his house, where there is some heat. Concrete post bases have been delayed a little as well, as it is too cold to pour concrete. Skin dries out and cracks. Gloves are too cumbersome for some of the work, and so skin bears the burden. Noses run. Eyes water. The construction goes on.
We are close to having the structure dried in, and then maybe we can get a heater going in there and keep things a bit more comfortable, but winter still has months of days on the calendar, and so we keep slurring words when we speak with one other because our lips are frozen. Funny how only miserable stuff sticks deep in your memory. I work out of my garage, which is pretty cold. When my kids are older, I will say, ‘back in my day, I worked in a cold garage, where my fingers froze as I typed…and I loved it!’.
Interested in what goes on with the body when exposed to the cold for a long time, I provide you with the following…
1. Sweat stops being produced.
2. The minute muscles under the surface of the skin called arrector pili muscles (attached to an individual hair follicle) contract (piloerection), lifting the hair follicle upright. This makes the hairs stand on end which acts as an insulating layer, trapping heat. This is what also causes goose bumpssince humans don’t have very much hair and the contracted muscles can easily be seen.
3. Arterioles carrying blood to superficial capillaries under the surface of the skin can shrink (constrict), thereby rerouting blood away from the skin and towards the warmer core of the body. This prevents blood from losing heat to the surroundings and also prevents the core temperature dropping further. This process is called vasoconstriction. It is impossible to prevent all heat loss from the blood, only to reduce it. In extremely cold conditions excessive vasoconstriction leads to numbness and pale skin. Frostbite only occurs when water within the cells begins to freeze, this destroys the cell causing damage.
4. Muscles can also receive messages from the thermo-regulatory center of the brain (thehypothalamus) to cause shivering. This increases heat production as respiration is an exothermic reaction in muscle cells. Shivering is more effective than exercise at producing heat because the animal remains still. This means that less heat is lost to the environment via convection. There are two types of shivering: low intensity and high intensity. During low intensity shivering animals shiver constantly at a low level for months during cold conditions. During high intensity shivering animals shiver violently for a relatively short time. Both processes consume energy although high intensity shivering uses glucose as a fuel source and low intensity tends to use fats. This is a primary reason why animals store up food in the winter.
5. Mitochondria can convert fat directly into heat energy, increasing the temperature of all cells in the body. Brown fat is specialized for this purpose, and is abundant in newborns and animals that hibernate.