Why temperature control matters
The outside of your body - your skin - may feel very hot on a sunny summer's day or very cold when it is frosty and snowy. But it is very important that your internal core temperature stays around 37°C whatever the weather and whatever you are doing.
Why is core temperature so important?How do enzymes work?
An enzyme is a protein molecule. Each type of enzyme catalyses a particular reaction or type of reaction. They can do this because the long chains of amino acids which make up the enzyme are folded into a particular shape known as the active site. This allows other molecules - the substrates of the reaction - to fit into the enzyme. This works like a lock and key. Once the substrate is in place in the active site it binds to the enzyme and the reaction then takes place rapidly. The products of the reaction are released from the surface of the enzyme.Enzymes are protein molecules which act as biologicalcatalysts, speeding up and controlling all the reactions taking place in the cells of your body. 37°C is the temperature at which these enzymes work best. A few degrees cooler and they work so slowly that the reactions in your cells do not go fast enough to keep you alive. A few degrees higher and the enzymes denature, so they cannot work at all and you will die.
All weather clothing
Intelligent developments are undoubtedly going to feature strongly in the textile & fashion industries over the next decade and even become a part of our everyday life. The so-called intelligence arises from the incorporation of particular components into the fabric, which may be electronic devices, specially constructed polymers or even some type of colorant. Many intelligent textiles are designed to respond to adverse conditions in their environment and there by provide enhanced protection. They can also either alter their nature in response to external factors or confer additional benefits to their users. There has been extensive innovation, for example, in clothing fabrics that can provide extra insulation in hot as well as cold conditions. Such textiles are becoming increasingly important in the fashion industry.
The first question, which may be asked, is what exactly is all weather clothing? A more technical term will be temperature-regulated or thermo-regulated clothing. To consider thermo regulation only as staying warm would be incorrect, or only half correct. The term is broader than that and actually means maintaining the body temperature to the level that will maximize performance and comfort, while also protecting the user. Temperature regulation or thermo-regulation is best defined by its goal, which is to maintain both the core body temperature and the comfort of the wearer in diverse environments. The body itself regulates its temperature through a group of biological processes. Even at rest the human body is a mass of ongoing chemical reactions that regulates body heat within an optimum temperature range called the thermo-neutral zone (usually set at 37+1oC). When the body temperature extends beyond the limits of the thermo-neutral zone, bodily systems operate less efficiently, and when pushed to extremes can even result in death. Therefore, thermo-regulation is critical both from a safety and performance standpoint.
Typically, fabrics do not inherently provide thermo-regulation. Their thermo-regulation is affected by not inhibiting or rather supporting the thermo-regulation efforts of the body itself. The role of the fabric will be to allow air to circulate around the body and at the same time provide a cushion of insulation (either hot or cold) when the body needs it. The fabric must be able to adjust to the needs of the body over a wide range of external temperatures and activities.
Certain combinations of fabric construction, chemical finishes and garment construction can also keep the body warmer or cooler, depending on the environmental conditions. Usually fabrics are geared for one or the other. Cold weather garments must address both radiant and convective heat loss. On the other hand, warm-weather garments must aid evaporative heat loss by increasing moisture movement, and increasing the velocity of heat conduction through the material. Control of airspace in the microclimate between the skin and the garment, or between layers is of prime importance.
There are three main characteristics that have been observed in materials that provide thermo-regulation. First is breathability/moisture management. The absorption and retention of water must be as close to zero as possible and there should be a mechanism to ensure that the moisture is moved away from the skin. The second characteristic is insulation. The fabric must have a good insulation value to supplement the boundary layer or air gap on the surface of the skin. There can be a mechanism to vary the degree of insulation. Last of all, the fabric must be lightweight with good bulk to achieve maximum comfort.
Hot & Cold:
Extreme Temperature Safety
If you intend to travel outdoors, you should be prepared to deal with all sorts of weather. This might mean the rainiest days to the driest, and from the hottest daytime hours to the coldest nights.
The human body has a normal core temperature between 98.6 and 99.9 degrees Fahrenheit (F). In order to maintain this temperature without the aid of any warming or cooling device, the external environment must be at about 82 F. Clothes aren’t just a social convention — they’re necessary warming tools. We can usually add on more layers in colder months, and use fans or air conditioners in warmer months in order to maintain that healthy core temperature.
However, in some cases, you may find yourself in an environment with temperature extremes. It’s essential to know what health concerns you may face, and how to avoid any temperature-related problems.
The Heat
It’s important to note that the temperature reading on a thermometer is not necessarily the temperature for which you should be concerned. The relative humidity in an environment can significantly affect what’s called the “apparent temperature,” or the temperature you actually feel. If the air temperature reads 85 F, but there’s zero humidity, it will actually feel like it’s 78 F, whereas the same air temperature in an environment with 80 percent humidity will feel like 97 F.
High environmental temperatures can be dangerous to the human body. In the range of 90 to 105 F, heat cramps and exhaustion may occur. Between 105 and 130 F, heat exhaustion is almost certain, and activities should be significantly limited. An environmental temperature over 130 degrees F is likely to lead to heatstroke.
Heat-related illnesses include:
- heat exhaustion
- heatstroke
- muscle cramps
- heat swelling
- fainting
One key to avoiding heat-related illness is to stay well hydrated. You should drink enough fluids that your urine is light colored or clear. Never rely solely on thirst as a guide to how much liquid you need to drink. In times of high fluid loss or significant sweating, be sure to replace electrolytes as well. Make sure you wear clothing appropriate to the environment. Clothes that are too thick or too warm can quickly cause a person to become overheated.
The Cold
As with high temperatures, when it comes to cold temperatures, don’t rely solely on the thermometer reading of environmental air. For instance, the speed of the wind and external body moisture can cause a chill that dramatically changes your body’s rate of cooling and how you feel. In very cold weather, especially with a high wind-chill factor, you can rapidly experience the onset of hypothermia. Falling into cold water can also result in immersion hypothermia.
When your body first drops below 98.6 F, you may:
- start to shiver
- have an increased heart rate
- have a slight decrease in coordination
- have an increased urge to urinate
When your body temperature is between 91.4 and 85.2 F, you’ll:
- decrease or stop shivering
- fall into a stupor
- feel drowsy
- be unable to walk
- experience quick changes between rapid heart rate and breathing to slow heart rate and shallow breathing
Between 85.2 and 71.6 degrees F, you will experience:
- minimal breathing
- poor to no reflexes
- inability to move or respond to stimuli
- low blood pressure
- possibly coma
A body temperature below 71.6 F is extremely dangerous. It can result in muscles becoming rigid, blood pressure becoming extremely low or even absent, heart and breathing rates decreasing, and can lead to death.
It’s essential to protect anyone experiencing early symptoms of hypothermia. They should be removed from the cold immediately if possible. However, don’t try to warm a person suffering from serious hypothermia with vigorous exercise or vigorous rubbing, because this can lead to more difficult problems.
Other cold-related illnesses include:
- frostnip
- frostbite
- trench foot (or “immersion foot”)
- chilblain
- Raynaud’s phenomenon
- cold-induced hives
Besides these illnesses, winter weather can cause major inconveniences for travelers. It’s important to be prepared to deal with heavy snow and extreme cold when on the road or at home.
Proper preparation and attention to emerging conditions can prevent or treat many temperature-related situations and ailments.
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