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Let's get started by discussing briefly the issue of being wet. Water next to your skin can be very beneficial or at times a very detrimental. It is very important to remember when water is next to your skin it will conduct over 20 times the body heat away from the body, than if water was not present. The body does not care where the water came from rain, perspiration or immersion, because all water is a conductor of heat and will remove heat from the body. In the summer we sweat to help remove the heat, as the sweat evaporates the body cools off. During colder days even 40 fahrenheit weather, if water is next to the skin, heat will be lost as it is conducted away from the body. Significant loss of heat [Hypothermia] or too much heat [Hyperthermia] can be life threatening.

What Is Hyperthermia?

Hyperthermia is a result of the body being over heated. Causes can be physical activity, moderate to high ambient air temperature, onset of dehydration as a result of losing too much sweat without adequate water intake to replenish your system, solar or reflected radiation, improper clothing which does not allow for evaporation [cooling] of sweat, a low fitness level and or additional workload of carrying excessive weight.

Symptoms Include:

1. Heat cramps may occur and should be treated by moving the victim to a shady area and supplying water and salt tablets.
2. Heat exhaustion is a mild form of hyperthermia and includes symptoms such as headache, dizziness, fainting, clammy skin, blurred vision, nausea and vomiting. Treatment is the same as heat cramps.
3. Heat stroke is the most serious degree of hyperthermia. The victim will have little or no perspiration, a hot and flushed face, full pulse, and become either apathetic or aggressive. Cool the victim as quickly as possible paying extra attention to the head, neck and chest. If the bodies temperature continues to rise, unconsciousness, delirium, convulsions and ultimately death may occur.

Rules of thumbs to avoid hyperthermia:

• Be very aware of your physical feelings during outdoor activities on hot humid days.
• Be smart, don't push things with over aggressive activities. Pace yourself, and seek shade as often as possible.
• Lay down on cool ground to allow the body to give off some of it's heat to the cooler ground.
• If you are fortunate enough to have water nearby, take a break and cool off in the water for ten minutes. Doing so will help you put a full day of putting one foot in front of the other, as you trek to your destination.
• Avoid activities in the heat of the day, higher than the low 90s Fahrenheit, if possible.
• Wear cotton next to skin - it absorbs water and will help draw-down the body temp as it evaporates.
• Wear a broad brimmed hat, to lessen the heating of your head.
• Rehydrate by drinking lots of water. Your urine should be clear as possible. Clearish urine indicates adequate hydration. The brighter the yellow, the more alarming is the dehydration with subsequent over heating.
• Take salt tablets as needed. The body sweats to induce temperature reduction and sweat includes salt in solution. The more a person sweats, the more salt their body loses. Taking small salt tabs with water replenishes the lost salt.

Recognizing and Treating Hyperthermia

When heat production exceeds heat loss, the body dilates its blood vessels, allowing more blood to pass near the skin to be cooled and increases the amount it sweats. If a person continues to produce heat without replacing fluids and salts, hyperthermia will follow. Heat cramps often occur before heat exhaustion sets in. By the time a person experiences the effects of heat exhaustion, they often have stopped exercising and slowed down their heat production. Usually (but not always) heat exhaustion precedes heat stroke. Since most people stop exercising when they start feeling sick, they usually will not develop heat stroke. However, if you do not care for a person who has heat exhaustion, or they do not stop producing heat (exercising), heat stroke will follow.

Perhaps you will find the following table helpful:

Condition	Signs	Symptoms	Severity	Action
Heat cramps	Heavy sweating, warm skin	Painful cramps in abdomen or legs; weakness; dizziness	Mild	Replace fluids and salts; massage muscle
Heat exhaustion	Rapid, shallow breathing; weak pulse; cold skin; heavy sweating	Weakness; nausea; dizziness	Moderate	Replace fluids and salts (if victim is conscious), cool by removing excess clothing
Heat stroke	Deep, then shallow breathing; full, rapid pulse; dry, hot skin	Weakness; dizziness; nausea	Severe	Cool rapidly; obtain or get to medical care

Additional Information Regarding Heat Related Complications

1. Heat cramps result from long exposure to heat, although the air temperature does not have to be much greater than "normal." A person who has heat cramps usually perspires heavily, often drinking large quantities of water. As the victim continues sweating, their body loses salts, bringing on painful muscle cramps, often in the abdomen and legs.
2. Heat exhaustion often occurs to healthy people exposed to excessive heat while working or exercising. The affected person suffers a mild form of shock caused by fluid and salt loss. Blood pools in their skin as their body attempts to get rid of its excess heat: you will notice that their face appears flushed. Heat exhaustion is more of a problem during the summer and reaches a peak during prolonged heat waves.
3. Heat stroke occurs when a person's temperature-regulating mechanisms fail and his or her body can not get rid of its excess heat. Effectively, the body can not sweat. This is a true emergency! More cases of heat stroke occur on hot, humid days; however, many cases occur from exposure to dry heat. Even though heat stroke commonly is called "sun stroke," it can result from excessive heat other than from the sun. All cases of heat stroke or suspected heat stroke are serious and require obtaining medical care immediately.

Tips on preventing hyperthermia include:

1. Being in good general physical condition.
2. Drinking adequate fluids during periods of heavy sweating. Never wait until you are thirsty, you're already dehydrated at that point.
3. Providing for adequate rest.
4. Wearing appropriate clothing.
5. Avoiding tobacco, caffeine, and alcohol [they imbalance your body's ability to regulate its temperature].
6. Being aware of the potential dangers of hot, humid weather.

What Is Hypothermia?

Humans require a fairly constant internal temperature [also called core temperature] of 98.6 šF or 37 šC to survive. Hypothermia can be a severe problem, for example, if someone gets sweaty while exercising hard and then cools down after stopping.

When most people think of hypothermia, they think of frigid temperatures in the dead of winter. However in conditions even as high as 40-50 degrees fahrenheit, hypothermia can occur, due to a number of reasons. The colder the ambient temperature though, the greater the chance. Let's create a little scenario.

You're on your way home in a very rural area outsider a small city. Suppose there was an terrorist event where by you could not get home. You come upon a road block and after the ID thing, and where are you going, you find out all roads leading home were closed. You figure, hey, I've got to get home to the family, so you grab what you can and head out. You head down a set of railroad tracks which you believe go through your town about 8 or 10 miles away. It's 3:30PM and the temperature is 65 degrees F. Sometime after dark, it starts to drizzle, then rain. It's stops in about an hour, but you're wet. You notice the wind is picking up and it's getting cooler. Being somewhat knowledgable about weather, you tell yourself a mild cold front has come through. You mutter to yourself something about stupidity. In the next several hours, the wind picks up further and you start shivering as you walk along. It's only 40 or so fahrenheit, but you are starting to enter hypothermia. You quicken your pace to generate heat, it doesn't help. Your thoughts drift as you try to figure out why you are so cold and you remember putting on a cotton t-shirt under your cotton long sleeve shirt before leaving home. By day break, you are nearing death as you huddle in a culvert near the tracks.

So what did you do wrong?

• You did not check the weather forecast.
• You did not have a Get Home Bag [GHB] in your car. GHB would have the right clothes to change into for the trip home on foot.
• You headed out late in the day, not thinking about normal cooling during the night.
• You headed out not realizing that cotton soaks up sweat, but keeps it next to the skin, where it continuously draw downs your body temperature.
• You made no effort to communicate your intentions.
• -----I could go on and on. Bottom line is lack or preparation and planning can kill you. It's that simple.

Recognizing Hypothermia:
When heat loss exceeds heat production, the body gives heat to the body core (heart, lungs, brain, and other internal organs) first. So, the body decreases blood flow to the body surface and extremities to decrease heat loss and maintain the core temperature. We perceive this, our first warning, as cold hands and feet. Our bodies (if not too exhausted) may also increase heat production by shivering (involuntary exercise). These are our only warnings, and they are not always obvious.

Without intervention, hypothermia will follow. Although different people may respond differently, the table below gives a general idea of the symptoms people exhibit as their body temperature drops. Frequently someone who is hypothermic will be confused and refuse care.

Hypothermia often follows other injuries and you must always consider it a threat in emergency situations. Remember that if you stand around because someone else is injured, you put yourself at risk of hypothermia. Additionally, frostbite (freezing of the skin or body) often accompanies hypothermia in cold weather and must be prevented.

Perhaps the following table will help you:

Body Temperature (core)	Symptoms
99 °F to 96 °F	Intense, uncontrollable shivering.
95 °F to 91 °F	Difficulty speaking.
90 °F to 86 °F	Comprehension dulled.
85 °F to 81 °F	Irrational. Stuporous state.
80 °F to 78 °F	Unconscious.
Below 78 °F	Pulse absent.

Rules of thumb for avoidance of hypothermia during cool or cold temperatures:

• Wear moisture wicking fabric such as wool or a synthetic equivalent next to skin to draw water away from skin and transfer it to the outer garments. You don't want water on the skin, as it will evaporate which is a cooling process and will draw more heat from the
• body. You want the water away from the skin.
• You want to have a GHB with a second helper bag [change of clothes and accessories to select from].
• You want to have knowledge of pending weather before you hoof-it, unless you have no choice.
• You want to have the ability to find or create a shelter to stay dry.
• You want to have available rain gear to help you stay dry.
• You want to have an emergency portable radio with a built in weather channel.
• You want to know where you are and have more than an idea of how to get to where you need to go.

Causes of Hypothermia:
We have many ways of losing body heat, but only one completely reliable way to make it-eat, drink, and exercise. Factors that increase the risk of hypothermia include:

Increased Heat Loss	Decreased Heat Production
Wet clothing (due to snow or sweat)	Exhaustion/fatigue
Inadequate clothing (during stops)	Poor food or water intake
Water immersion	Poor physical condition
Alcohol or drug ingestion	Drug ingestion
Wind chill	Psychological factors: fear, isolation, or withdrawal

Treating Hypothermia:
You can do the following things if you suspect someone may be hypothermic while you seek professional assistance:

1. Reduce exposure by getting shelter from wind or rain.
2. Remove wet clothing and replace with dry.
3. Cover the head, neck and hands with hat and mittens.
4. Provide heat in the form of warm (not hot!) liquids. Provide adequate food and calories to increase heat production. Do not give alcohol or caffeine!
5. If the victim is not exhausted, increase their heat production by getting them to exercise. This is the best way to warm someone who has cooled off too much when they stopped exercising.
6. If and only if the victim can not move, place them in a sleeping bag without wet clothes. Insulate them from the ground with a pad or two. Provide heat from warm (not hot!) water bottles and keep the victim inactive until they show some signs of improvement. Providing heat from another body is difficult in the field and is presently considered controversial (not for personal reasons, but for medical and group-safety reasons).

An unconscious hypothermia victim needs professional medical help. Stabilize the patient in a sleeping bag, as above, but do not apply warm water bottles. Do not move them and do not perform CPR unless you have very extensive training: severely hypothermic patients are fragile, and this may kill them.

What Is Frostbite?

1. Frostnip the least severe stage, results from direct contact with cold objects or exposure of body parts to cold air (particularly the tips of the nose, ears and fingers, and the upper cheeks). Minor tissue damage results, often with good response to care.
2. Superficial frostbite involves the skin and tissues just beneath the skin. Greater (deeper) tissue damage results than in frostnip, and response to care varies.
3. Freezing involves deeper structures of the body, including muscles, bones, deep blood vessels, and organ membranes. Ice crystals can form in the skin causing local tissue death (gangrene) that can lead to the loss of the body part.

Causes of Frostbite:
Exposure to cold alone does not necessarily lead to frostbite; certain predisposing conditions almost always exist. These include fatigue, dehydration, fear and poor nutrition. An individual who has had an accident is more susceptible to frostbite than an uninjured person.

Recognizing Frostbite:
As frostbite sets in, the affected area feels cold, and then loses all feeling. As the area gets colder it may even begin to feel warm. The table below describes the symptoms of frostbite in its different stages.

Condition	Skin Surface	Tissue Under Skin	Skin Color
Frostnip	Soft	Soft	Red, then white
Frostbite	Hard	Soft	White and waxy
Freezing	Hard	Hard	Blotchy, white to grey

Treating Frostbite

You can easily treat frostnip. As soon as you detect a blanching of the skin, rewarm the affected area. You can treat a frostnipped ear or cheek by covering it with a warm hand or mitten; if fingertips become frostnipped, place them in your armpits for rapid rewarming. Never rub a frostbitten area with anything. Doing so may cause further tissue damage.

A slight tingling or burning sensation accompanies thawing of superficial frostbite. Blisters occasionally form in a moderately frostbitten area. Take care to avoid breaking the blisters to prevent infection.

Treatment of frozen tissue is critical Improper rewarming, or refreezing of the area after rewarming, usually results in more damage than leaving the frostbitten area alone-frozen-until you can get to a medical facility where proper rewarming can be done. A person can walk on frostbitten feet for hours and maybe days without doing much more damage. If you rewarm his or her feet, you would have to carry him or her out with the added risk of refreezing the area.

Preventing Frostbite and Hypothermia:
Preventing frostbite is much simpler than treating it. To avoid it, people must protect themselves against cold, moisture and wind. Frostbite rarely bothers the well-equipped, careful, alert participant. Frequently, victims are ill-equipped, inexperienced, and unprepared.

Tips to prevent frostbite include:

1. Being in good general physical condition.
2. Drinking adequate fluids (at least 1 to 2 liters per day).
3. Eating ample food to produce maximum output of body heat.
4. Providing for adequate rest.
5. Wearing appropriate insulating clothing that does not fit too snugly.
6. Keeping dry by avoiding perspiring. Protect your face, neck and head.
7. Keeping your hands and feet warm by minimizing their exposure to extreme temperatures and avoiding any bare skin contact with metal (stove, camera, etc.).
8. Avoiding spilling fuel on skin or clothing.
9. Watching your companions for signs of frostbite (light or white patches)-especially on their noses, ears and cheeks.
10. Avoiding tobacco, caffeine and alcohol.
11. Making sure your boots do not impede circulation in your feet.
12. Being aware of the dangers of cold weather: alertness and common sense are by far your best protection against frostbite injuries.

What Is Hydration vs Dehydration?

Drinking ample amounts of water is one of the most important aspects of surviving outdoors and or indoors, with emphasis to the outside during heavy strenuous activity:

1. Outdoor survival activities often impose high energy demands on the body. In parts of the food-burning process, the body must use water to make new energy.
2. Even during cold weather, high sweat rates often accompany strenuous activity such as carrying a heavy backpack.
3. The human body requires an adequate body-water percentage to keep its metabolism going at the energy levels needed for extended exercise.

If you are in a group and one of your group members becomes dehydrated by even 5%, they can experience a 20 to 30% decrease in their metabolism, an effect they certainly feel. Mild dehydration results in headache, weakness, fatigue, irritability, loss of appetite, and decreased resistance to hot and cold. You can estimate your state of hydration by checking the color of your urine: clearer means that you are better hydrated, darker yellow indicates dehydration. In the winter, you can tell if any of your group members are dehydrated using this method, but more likely, you will need to make sure they remain hydrated by providing plenty of water stops.

Keep in mind that when we exercise, particularly in cooler weather, our thirst mechanism becomes suppressed, and it often requires conscious effort to drink enough. On a typical day on the move, we lose four liters of water (about one gallon), more than most people probably drink. You should encourage your group to load up on water (and calories) before heading out, perhaps by drinking a liter of water with breakfast, and they re-hydrate again after finishing the day's trek. Each person still should drink two to three liters of water during the day. However, it doesn't do any good to drink too much water at once. Our bodies can not absorb it that fast, and it will go right through us.

Along with water, our bodies also need electrolytes. Body fluids contain minerals such as sodium, potassium, calcium, and others, that keep muscles contracting and nerves working. Gatorade-type drinks help, as do certain foods (such as bananas). In today's world salt tablets are seldom recommended as there are plenty of nutritional supplements which can be taken which are far more effective than plain salt.

Unfortunately, no matter where you are trekking through you cannot simply dip your cup into the nearest clear, running mountain stream and drink. Most body of waters have become contaminated with Giardia, a nasty bug that causes extreme intestinal distress.

Preventing Dehydration

The leader of a group is always responsible for masking sure members carry adequate amounts of water. If that person were you, then you should plan how much water you expect participants to carry on any leg of a trip, and make sure they carry it. Besides personal drinking water, there may be group needs for water, such as cooking.

As a leader it would pay off in the end if you make sure all members of your party understand the following:

• Caffeine suppresses both thirst and hunger sensations and causes our kidneys to remove water from our bloodstream faster than they normally would (i.e., caffeine is a diuretic). Not only are we dehydrating ourselves by taking a diuretic, but we also are fooling our bodies into believing they are not hungry or thirsty. Caffeine comes in many of our favorite drinks like coffee, tea, and hot chocolate (or any chocolate, for that matter).
• Alcohol also acts as a diuretic. In addition, it dilates the blood vessels of the skin, giving a false sense of warmth and affecting our thermal regulation and sweat control (to say nothing of its effect on our judgment!).

In reality, many people will not give up their morning coffee. In fact, we listed suggested quantities of coffee to bring for group meals. However, remember that many factors combine to affect the safety of the group. Drinking a diuretic may not matter on a spring day trip with good weather, but it may cause a significant safety hazard on a winter trip with unpredictable weather.

Notation:
Other issues are very relevant to the information discussed within this webpage. Those topics are partially included below. No list can be complete for things to all forms of emergencies and conditions:

• Adequate preparation for survival outside or inside during conditions which could lead to physical illness and harm.
• Having prepared a plan of action to be referred to during and emergency
• Communication planning in case of a medical emergency
• Emergency medical kits available during the emergency you are struggling with.
• Water supplies, that is foraging for water when normal sources fail.
• Purification of any water located prior to ingesting.

Information presented within the pages of this web site as well as hyperlinks to other remote pages, is presented for informational and educational purposes only. Please refer to our Disclaimer Page before proceeding and or leaving this website.

Last edited on ... March 15, 2007
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