Why do we sweat? Sweating is the body’s natural way of cooling us down. Although it may feel as if the sweat or perspiration is making us hotter, especially.

Why do we sweat?

• Sweating is the body’s natural way of cooling us down. Although it may feel as if the sweat or perspiration is making us hotter, especially on warm days, without sweat, we would not be able to tolerate the heat our bodies would produce.

Normal Body Temperature

• We sweat in order to keep the body at its normal temperature, which is 37 degrees Celsius.

• If we lost this bodily function we could suffer from heatstroke in hot weather.

Burning Food

• Think of all the food the body takes

in each day. This has to be burned

off somehow.

• The burning of this food produces heat within the body which triggers our brain to kick start the body’s natural cooling process.

• Inside the human body are long, twisting tubes of cells known as the sweat glands. The blood vessels in our skin open and the fluid is released through our pores.

How many sweat glands?

• There are approximately 2 million sweat glands in our body.

• You should aim to drink 2L of water each day.

What is in sweat?

• The most common elements are water and sodium, otherwise known as salt. At times, we can have a low sweat production--this happens when it is cool and we are resting. The higher sweat production occurs in very hot weather or when we are exercising.

Perspiration?

• Perspiration that is produced through the aprocrine glands, or in the armpit, will be thicker and perhaps have a yellowish color. This is because it contains fatty acids and proteins. It is this type of sweat under the arms, coupled with antiperspirants, which can turn clothing yellow.

You stink!• When we apply deodorants it is only to the

armpits, in order to counteract the smell of the Aprocrine sweat.

• Sweat is actually odorless, but when it starts to decompose and is attacked by bacteria, the smell can be unpleasant.

What are Goose Bumps?

Goosebumps are caused by cold weather or by extreme emotions like fear.

Similar to a porcupine, the tiny hair in our body stand upright when the hair follicle muscle is stimulated to contract.

Goose Bumps

• Goose bumps are often a response to cold: in animals covered with fur or hair, the erect hairs trap air to create a layer of insulation.

• Goose bumps can also be a response to anger or fear: the erect hairs make the animal appear larger, in order to intimidate enemies.

Why do we shiver?

• Your body has its own automatic or reflex way of making muscles work just under your skin.

• When your receptors sense that your internal body temperature is getting too cold they constrict or close the blood vessels at the surface of the skin to move blood inwards towards your heart.

Shivering to stay warm?

• Shivering is one of the methods that the human body uses to warm itself. 

• It is a neurological (brain/nerve) reaction, that the body executes when it gets too cold.  

• Joggers are familiar with the concept of moving to stay warm; they run in the coldest of weather and manage to stay warm.  

Warming up

• Basic physics dictates that energy taken from a storage source (like our fat) and changed to another form of energy (your body movements), results in yet another form of energy - heat. 

• So when your muscles start moving back and fourth rapidly, they make heat, which helps warm the body in the cold.  

Acclimatization

• Some people have a different tolerance for cold, and in fact those who shiver easier, can withstand colder temperatures.  Specific tolerances can change as we adapt over long term exposure, which is why all those Florida natives look at you funny when you wear your shorts down there in January, they have just adapted to the warm temperatures. 

What is frostbite?

• In cold temperatures, skin that is not properly covered or protected can freeze quickly.

• The most common body parts to have frostbite are the cheeks, ears, nose, hands, and feet.

• Skin that is not covered in the cold will first become red and swollen and it will feel like it is stinging or burning.

What is frostbite?

• If skin remains exposed to the cold, it will feel like it is tingling and will look grey. If it freezes, the area will have no feeling and it will be shiny and white.

• Frostbite can happen in cold wind, rain, or snow.

• Once a part of the body has had frostbite, it is more likely to happen again.

Treating Frostbite

• Gently remove any clothing covering the area and

• Slowly re-warm the area by gently covering the ears or nose with a hand and placing a frostbitten hand in the opposite armpit.

• Do not massage or rub snow on frostbitten skin; do not use heat or warm water to warm the skin.

• Call your doctor for treatment.

Shivering is serious

• Shivering is a sign that hypothermia is setting in as well, it's a very early sign, but uncontrollable shivering should be taken seriously. 

What is Hypothermia?

• Mild Hypothermia: Shivering - if shivering can be stopped voluntarily, it is mild hypothermia. Can't do complex motor functions with hands but can still walk and talk. Skin is cool due to vasoconstriction. Hands numb. Moderate confusion - if you cannot count backwards from 100, you may be hypothermic.

Moderate Hypothermia

• Shivering not under voluntary control. Loss of fine motor control—particularly in hands—can't zip up coat—due to restricted peripheral blood flow.

• Poor coordination. May have: Dazed consciousness.

• Slurred speech. Violent shivering. Irrational behaviour—may even undress. Unaware that you are cold. "I don't care" attitude. Flat emotions.

Severe Hypothermia

• Shivering occurs in waves until shivering finally ceases.

• Irrational.

• May seem normal. Progresses to: Can't walk, curls up into fetal position to conserve heat. Muscle rigidity. Skin is pale. Pupils dilate (become big). Pulse rate decreases. Then breathing rate decreases. Then the person looks dead, but is still alive.

Risk factors for hypothermia

• Cool, cold, wet, or windy weather. Improper clothing and equipment.

• Clothes that are tight and impair circulation. Fatigue. Dehydration. Extremes of age. Immobility. Not eating enough. Alcohol, cigarettes, caffeine.

• Not taking hypothermia seriously.

Risk for Hyperthermia

• Highest risk = days when the weather changes a lot, when its cool but not cold, or when people don't anticipate the cold, wet, and/or wind.

• Remind you of Nova Scotia weather?

Medical conditions that increase risk of hypothermia

• Hypothyroidism (the endocrine system helps with the body's temperature regulation)

• Hypoglycemia• Malnutrition • Skin problems (can cause increased

circulation to the skin which increases heat loss)

• Head trauma (impairs the body's temperature regulation)

Preventing Hypothermia

• Dress for the weather

• Stay Dry

• Eat!

• Drink Water

• Don’t drink alcohol

• When you start to feel cold, try to warm up

Treatment

• Get warm

• Get dry

• Drink lots of liquids

• Eat (candy, juice, chocolate, fruit)