The Body Temperature Regulators Staying Warm or Keeping Cool

Dec 11, 2017

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This article was edited and updated on December 22, 2021.

Are you imagining it...or is it harder to stay warm when you're older?

(Photo by Bob Ingraham)

No, you're not. As we get older, it actually gets harder to stay warm! In the photo at left, I am taking one of my earliest outings in an Ottawa winter. It was very cold!

There are several reasons for this:

As the walls of the blood vessels lose elasticity, there is a decrease in circulation;
The layer of fat under the skin begins to thin (it helps to conserve body heat);
Metabolic responses to the cold are slower;
If you become less active, circulation is reduced, making you feel colder;
If you lose weight, less fat storage means less insulation, causing you to feel cold;
The areas of our body where there is less circulation — hands and feet — are especially more likely to feel cold.

The bad news is that researchers are not sure if older people are actually colder, or if they just feel colder. Feeling cold may be, at least in part, a subjective response to the environment. (By the way, for those of us who feel the cold, this information is of no use to us!)

The good news is that an increased sensitivity to the cold does not usually pose a big health risk, or require any specialized medical treatment, but be aware that being cold all the time may be an indication of an underlying health issue, including these conditions:

Anemia. When you don't have enough healthy red blood cells, you can feel cold.
Anorexia. The loss of body fat as a result of this condition can be fatal.
Hypothyroidism. If the thyroid doesn't produce the hormones necessary to help regulate the body's temperature, a person may feel cold all the time.
Blood vessel (vascular) problems. These disorders (which includes Raynaud’s phenomenon) restrict blood flow to the extremities. Fingers and toes can go numb and turn white; as they warm up, they tingle and can even hurt.
Disorders of the hypothalamus. The hypothalamus is critical to producing hormones that control body temperature. If it is not functioning correctly, feeling cold all the time can be a symptom.
Fibromyalgia. Much mystery still surrounds this condition, but it can be painful and long-lasting. Some research shows that people with this condition have abnormal body temperatures, an inability to adapt to changes in temperature, and a lower pain threshold to both heat and cold stimuli.

So....how does this happen?

So how does our body control its temperature?

Here are the parts of our body that help to regulate temperature:

The body's Integumentary System includes the skin, hair, nails, and sweat glands. It has several purposes: (1) acts as a barrier to protect the body against diseases, (2) helps to retain body fluids, (3) eliminates waste products, and (4) regulates body temperature.
Hormones are chemicals produced in the body that controls and regulates the activity of cells or organs. Many are secreted by special glands, such as the thyroid hormone produced by the thyroid gland. The main hormone-producing glands are the hypothalamus (discussed below) and the parathyroid which controls the amount of calcium in the body.
The brain's hypothalamus regulates feelings of thirst and hunger, helps to control body temperature, and releases many hormones. The hypothalamus controls body temperature by triggering changes — everything from activating sweat glands to controlling muscles and body hair. Much like a thermostat regulates the temperature inside a home, the hypothalamus responds to the environment and makes adjustments. Most of the time, your body is close to 37°C (98.6°F). The hypothalamus deals with a complex set of temperature-control activities. It does the following: (1) balances body fluids; (2) maintains salt concentrations; (3) controls the release of chemicals and hormones related to temperature; and, (4) works with the skin, sweat glands and blood vessels to control temperature. For example, the middle layer of the skin stores most of the body's water. When you get warm, sweat glands are activated which brings water and salt to the surface (sweat). On the surface of the skin, the water evaporates, cooling the body and keeping the temperature in the right range.
Homeostasis is the ability to keep a system at a constant condition. Our bodies are constantly adjusting to the outside temperature: whether it is cold or hot, we have to adapt.

Remember: Too hot or too cold is not good. Heat stroke happens when the body becomes too hot. Hypothermia occurs when the body becomes too cold. Both can cause death if not corrected.

Extreme Cold

From the Mayo Clinic website:

"Hypothermia occurs when your body loses heat faster than it can produce heat, causing a dangerously low body temperature. Normal body temperature is around 37° C (98.6°F). Hypothermia occurs as your body temperature falls below 35° C (95°F). It is a medical emergency and needs immediate treatment.

"When body temperature drops, your body's organs and systems cannot work normally. If left untreated, it will lead to complete failure of your heart and respiratory system and eventually to death.

"Hypothermia is often caused by exposure to cold weather or immersion in cold water. Treatments are whatever methods can be used to warm the body back to a normal temperature."

Long before hypothermia sets in, there are many things one can do to stay warm when it's cold outside.

Skin that has been previously injured, such as by frostbite, may remain sensitive to cold even after the injury has healed.

How to Stay Warm

In the wintertime, it's not only colder outside, it's also colder inside unless you take steps to (of course) turn on the heat. Sometimes, a little extra clothing will help, too.

Whether you are cold because the outside temperature is cold, or whether you suffer from cold intolerance as a result of a medical condition, here are some ways that you can stay warm:

Wear warm clothing. Warm clothes can prevent body heat from escaping from your head, face and neck. Wool clothing retains more body heat than synthetic fabrics.
Wear mittens instead of gloves. Mittens allow your fingers to share heat. Your fingers will stay warmer in mittens than in gloves.**Wear protective covering to prevent body heat from escaping from your head, face and neck. Cover your hands with mittens instead of gloves.
Wear a hat. A hat prevents body heat from escaping from the top of your head.
Avoid overexertion or adhere to sensible procedures when exercising in the cold. Avoid activities that would cause you to sweat a lot. The combination of wet clothing and cold weather can cause you to lose body heat more quickly. If you do exercise or do outdoor activities, dress appropriately, and get into dry clothing as soon as possible.
Dress in layers. Wear loosefitting, layered, lightweight clothing. Outer clothing made of tightly woven, water-repellent material is best for wind protection. Wool, silk or polypropylene inner layers hold body heat better than cotton does.
Stay dry. Remove wet clothing as soon as possible. It's important to keep your hands and feet dry, so mittens and boots become very important.
Move...Exercise. If your feet and hands are cold, a little walk or some exercise will get the circulation going again and warm you up.

Extreme Heat

When we are too hot, blood vessels supplying blood to the skin can swell which allows more warm blood to flow near the surface of the skin, where the heat can be lost to the air.

As cimate change increasingly affects our planet, many people around the world are enduring hotter temperatures, particularly in the summer.

How to Stay Cool

Most of us sweat on a hot day just working around the house or taking a walk. And most of us sweat during fitness class — some more than others.

Here's what you need to know about sweating:

It is a natural process and a vital tool for good health.
We sweat because of an increase in body temperature — the body loses heat when sweat evaporates from the skin, thus allowing our bodies to retain a safe temperature while exercising.
It is the most effective way for the body to get rid of heat and maintain a safe internal temperature.
Sweat is your body’s natural way of providing a high-tech cooling system: it’s a good thing!
On a small scale it can burn calories in conjunction with traditional training. Sweating is a form of exercise, as the actual sweating process takes energy (around 300 calories per hour for a typical sweat). Therefore, sweating can help with weight loss and will increase metabolic rate.
It's believed that sweat will improve circulation and boost the body’s immune system.
Exercise associated with sweat releases endorphins into the body, making you feel less stressed.
The capacity to sweat is determined by genetics, age and gender, fitness level, and heat acclimation. It also matters what we wear because some materials can impede heat loss by reducing the evaporation of sweat.
As physical fitness improves, sweat loss increases.
Sweat tastes salty because it contains salt, minerals, amino acids, and metabolites, but it is 99% water.
The risk of heat illness is greater in unfit, unacclimated people, partly because their bodies heat up more before sweating begins. If you stop sweating, you may be headed for heat exhaustion or heat stroke (the more serious of the two).
There are medical conditions and medications that will affect your perspiration rate. If you are finding that you are suddenly sweating more, or less, or if you are uncomfortable with the volume of sweat that you produce, then you may wish to seek medical advice.

There is a big difference between a healthy sweat and a body that's overheated, so remember these two points:
* If your body reaches too high a temperature you can experience cramping, nausea and lose consciousness.
* If you STOP sweating, you may be overheating and heading for heat stroke, a very serious condition.

Remember these three simple rules about exercising in hot weather:

Wear light, comfortable clothing.
Always have a bottle of water for hydration.
Let sweat regulate your body's temperature, but if you get overheated, stop exercising, drink water, and rest for a time.