Let's explore the anatomy of cells and understand why they are affected by changes in temperature.
Total body fluid content of a healthy adult's mass is around 60%. That is a lot of liquid! This also makes us more subject to fluctuations in external temperatures. If you were to place an ice cube in direct sunlight and increase the temperatures, the water molecules change state and eventually enter the atmosphere as water vapour.
This is the same process that sweating performs, ridding the body of heat via evaporation. If you were to place water vapour in the freezer, the opposite reaction would occur ending with a solid. All of this fluid protects the organelles of the cell which allow them to perform their respective functions.
What is the risk of cells close to the surface of the skin beginning to freeze?
The most obvious of these conditions is known as frostnip and the more advanced frostbite which consists of superficial and deep, the latter of which can result in amputation of the affected tissue.
- Frost nip. The most common and mild involving the sensation of pins and needles, numbness and an achiness. This might happen when you've taken off your gloves to try and finish a text message, and your typing starts to slow down.
- Superficial frostbite. The skin begins to take on a mottled appearance as the colour shifts to bluish-white and becomes rigid to touch. This occurs as the fluid in the cells begins to freeze.
- Deep frostbite. The skin has become black as the cells die, entering a state of necrosis. The tissue has frozen down to the level of blood vessels, nerves, and bone, causing irreversible damage. The tissue will no longer have function and this stage is classified as a medical emergency. Seek help immediately.
What happens if the cold weather starts to affect our core body temperature?
Most of the time, the body sits at a comfortable 37°C. At this temperature, all of the cellular processes and biochemical reactions occur at peak efficiency. As core temperature shifts, whether to warm or cool, these reactions stop working as well. The same can be thought of many processes occurring in our daily lives, including the ignition of a combustion engine in a vehicle. When temperatures drop, the fluids in various lines of the vehicle become thicker and cause more friction which means it could take longer for your vehicle to reach peak performance.
When the core temperature drops to around 35°C, you enter a state of mild hypothermia characterized by vigorous shivering and difficulties managing self. As the temperature continues to drop beneath 32.2°C, this is considered moderate stage hypothermia. The individual may have weak shivering that comes and goes in addition to experiencing confusion and a lack of coordination or speech.
When core temperatures plummet under 28°C, the body has entered a state of severe hypothermia characterized by a lack of shivering, the body becoming stiff, and potentially a complete lack of pulse due to severely reduced circulation as the heart slows.
What are some important lifestyle factors to consider?
- Let that timeless advice ring through your mind for a moment – 'You can always take layers off if you get too warm, but you can't conjure them up if you feel cold'. When temperatures begin to dip, our heat-producing body conjures something known as a boundary layer. This is a thin, insulating layer of heat surrounding the body due to small convection currents as the heat moves away from the surface of the skin, interacts with the cooler temperatures, and falls back down to the surface. This boundary layer is whisked away by winds, the reason we see the predicted temperatures and those of the wind chill.
- Cut out the booze. Alcohol can impact one's ability to accurately perceive temperature, and this miscalculation could be costly as seen with the conditions discussed above. Alcohol dilates the blood vessels and shunts the blood from warming the core to the extremities, where overall temperatures are more susceptible to the influence of external temperatures. There are also the cognitive effects of alcohol where your executive function that would normally suggest to wear a coat on a cold walk home is gradually silenced.
- Boost your blood flow. A variety of remedies can influence blood flow, including certain herbs such as Ginkgo biloba. The ginkgolides are the active component in the herb and convey its ability to dilate blood vessels. These compounds seem to have an affinity for the cerebrovascular system, part of the core and arguably the most important tissue to keep warm by promoting blood flow. Certain products such as Ginkgo contain fresh ginkgo leaf extract and are an easy way to promote blood flow. Vasoconstriction is also related to the development of frostbite as blood circulates too slowly to maintain the temperature of the tissues, so widening these tissues can help maintain warmth.
- Exercise. This has been shown to induce a thermal response in the extremities, keeping the cells warm and perfused.