Hypothermia
Today I would like to talk about Hypothermia. Hypothermia is the lowering of the body's core temperature to a level where normal brain and muscle functions are impaired. It typically happens when several things occur simultaneously: low temperatures (<40F/4.5C), wet conditions (damp clothes), lack of fuel and hydration (food and water), and physical fatigue. This cascade of problems causes our thermoregulatory system to fail. Below I am going to lay out the stages of hypothermia,type of hypothermia, as well as treatment and prevention. First I would like to share a true story from my past.
Years ago on a camping trip I was caught out in a thunder storm on a hike. I did not prepare for any rain and I ignored the likely possibility of rain during Arizona monsoon season. I failed to make and preparations for any possible emergencies. The hike took longer than I had thought it would and by the time I had reached camp I was soaked down to my skin. My change of clothes was in my truck. Unfortunately my friends had left camp in my truck to re supply our food, water tanks and beer. The sun was starting to set and the temperature was dropping for the mid 60's. Our fire ring was now a puddle of water and mud. I moved some rocks and gathered some firewood and broke it up. I had a fero rod and some dried long grass but everything was soaking wet. I tried and tried to get a fire going as the temperatures dropped with the sun. I had started to shiver so violently that I could hardly coordinate a spark and eventually I gave up all together and sat on a stump until everyone returned to camp. By the time my friends returned 2 hours had passed. As they unloaded the truck with the supplies and joked about how It was unlike me not to have a fire going my friend started to notice that something was off. After talking to me and my unusual responses his first assumption was that I had started the festivities without them and that I was already drunk. He quickly started putting the pieces together and noticed that there was something more serious going on. He saw my wet clothes and shivering and started handing out orders. Blankets over here, get a fire going and some hot water or coffee, get those wet clothes off of him, get him dry and wrap him up. It was a while before I snapped out of my drunk-like daze and didn't really understand what had happened. Hypothermia happened and it could have been completely avoided. Without my friends knowledge and quick actions that camping trip could have gotten much worse for me. That was the first moment that I realized that a outdoor lifestyle required my respect and attention. Months later I enrolled in a Wilderness First Responder course and a year after that I went through a Wilderness EMT course and many other courses and instruction related to hiking, and secluded travel and safety.
*Disclaimer*
Before we go any further please know that I have done my best to provide the most accurate information available. Though I am a Nationally Certified WEMT, it is a hobby of mine and not a working career. Please use this article for information and awareness and seek professional medical help and advice when needed.
Stages of Hypothermia
98.6F (37C)
Physiology:Walking and talking. All systems functioning
Cognition:Mentally sharp, paying attention to details, monitoring our environment, and responding appropriately.
Behavior: Physically coordinated,feeling strong and capable, making appropriate gear and clothing decisions, setting a pace appropriate for the conditions, eating and hydrating properly.
97F (36C)
Physiology: Brain functions slow.
The thermoregulatory center in the brain, sensing heat loss, will initiate several defensive actions.
It will vasoconstrict and reduce blood flow to the skin, creating an additional thermal layer to prevent further heat loss.
Piloerection occurs. That is when our hairs stand up on end to attempt to create an insulating of dead air space.
The rate of metabolism will increase, burning more glucose to produce heat.
Cognition: Judgment begins to fail.
We become more focused on the trail in front of us and less aware of the weather and our surroundings.
Enthusiasm wanes and apathy sets in.
Behavior: Protective instincts fade.
We don't make the best gear and clothing decisions. We don't make thee best food and hydration decisions. Our mood and reactions change and we become more withdrawn.
96F (35.5C)
Physiology: All systems are on full alert, and the body is doing everything possible to rewarm itself from the inside.
Shivering begins as a constant, uncontrollable, fine motor tremor, and is caused by opposing muscle groups acting against each other. Shivering produces heat, but it is wasteful exercise that doesn't produce useful work and interferes with activities that require precision: Lighting a stove, pulling a zipper, swinging and ice axe.
Decreased fine motor skills. We begin to lose dexterity and our speech begins to slur.
Metabolism increases to meet the new fuel demands.
Cognition: Mental abilities are falling rapidly. Decision-making, judgment, and “common sense” begin to fail. Self Preservation instinct are replaced with a “summit or bust” mentality.
Behavior: In the face of changing weather (e.g, Drop in temperature, Increase in wind). We may not take any construction action (.e.g putting on another layer). We may leave clothing or equipment behind.
94F (24.5C)
Physiology: Shivering is at its maximum, but other systems are slowing.
Metabolism is peaking, but fuel is being burned at such a furious rate(up to five times) that the stores will not last long(4-5 hours, rather than the typical 24) When the stores are used up the shivering will slow and eventually cease.
Cognition: We are not aware of being cold. We believe that we are thinking clearly, but we're not. Simple problem solving is impossible( we can't do basic addition/subtraction). When confronted with obvious problems, we may agree, but don't really care.
Behavior: Coordination fails, tripping and falling begins. We have trouble staying on the trail and easily become lost.
We don't take care of ourselves( if we lose a crampon or a mitten or get snow down our back , we don't do anything about it)
Still, we remain goal- oriented-onward to the top/end
92F (33.3C)
Physiology: Shivering become intense.
Cognition: Mentally, we are beginning to shut down. We enter a dream-like state where nothing seems real
Behavior: We're unable to walk though we may still be crawling toward the goal. Speech becomes very difficult.
90F (32.3C)
Physiology: Shivering becomes convulsive and begins to fail. Shivering is violent for a minute, then absent for a minuet. We are running out of fuel and energy and shivering will soon cease.
Cognition: We can still be aroused, and will try to answer questions, but our speech will be slurred, perhaps beyond recognition.
Behavior: Curling and mumbling. We adopt the fetal position( the body's last ditch effort to protect the core and minimize heat loss. As things deteriorate, we become less and less arousable, and as the final glucose stores are burned, our shivering mechanism begins to fail.
86F (30C)
Physiology: We become unconscious, ashen, and gray.
We enter a “Metabolic Icebox” (essentially suspended animation). All systems have slowed to minimize the consumption of oxygen and sugar.
The blood is 190% thicker than normal, Preventing a palpable pulse.
Heart sounds will be absent.
Respirations will slow to 3-6 per minute and so slow and shallow they may be impossible to detect.
We may appear dead: pulse less and breathless with cold, stiff skin and fixed pupils.
There is an expression for this situation.” a person is not dead until they are warm and dead”
Cognition: We are comatose and unresponsive to verbal or painful stimuli.
Behavior: We initiate no action.
Today I would like to talk about Hypothermia. Hypothermia is the lowering of the body's core temperature to a level where normal brain and muscle functions are impaired. It typically happens when several things occur simultaneously: low temperatures (<40F/4.5C), wet conditions (damp clothes), lack of fuel and hydration (food and water), and physical fatigue. This cascade of problems causes our thermoregulatory system to fail. Below I am going to lay out the stages of hypothermia,type of hypothermia, as well as treatment and prevention. First I would like to share a true story from my past.
Years ago on a camping trip I was caught out in a thunder storm on a hike. I did not prepare for any rain and I ignored the likely possibility of rain during Arizona monsoon season. I failed to make and preparations for any possible emergencies. The hike took longer than I had thought it would and by the time I had reached camp I was soaked down to my skin. My change of clothes was in my truck. Unfortunately my friends had left camp in my truck to re supply our food, water tanks and beer. The sun was starting to set and the temperature was dropping for the mid 60's. Our fire ring was now a puddle of water and mud. I moved some rocks and gathered some firewood and broke it up. I had a fero rod and some dried long grass but everything was soaking wet. I tried and tried to get a fire going as the temperatures dropped with the sun. I had started to shiver so violently that I could hardly coordinate a spark and eventually I gave up all together and sat on a stump until everyone returned to camp. By the time my friends returned 2 hours had passed. As they unloaded the truck with the supplies and joked about how It was unlike me not to have a fire going my friend started to notice that something was off. After talking to me and my unusual responses his first assumption was that I had started the festivities without them and that I was already drunk. He quickly started putting the pieces together and noticed that there was something more serious going on. He saw my wet clothes and shivering and started handing out orders. Blankets over here, get a fire going and some hot water or coffee, get those wet clothes off of him, get him dry and wrap him up. It was a while before I snapped out of my drunk-like daze and didn't really understand what had happened. Hypothermia happened and it could have been completely avoided. Without my friends knowledge and quick actions that camping trip could have gotten much worse for me. That was the first moment that I realized that a outdoor lifestyle required my respect and attention. Months later I enrolled in a Wilderness First Responder course and a year after that I went through a Wilderness EMT course and many other courses and instruction related to hiking, and secluded travel and safety.
*Disclaimer*
Before we go any further please know that I have done my best to provide the most accurate information available. Though I am a Nationally Certified WEMT, it is a hobby of mine and not a working career. Please use this article for information and awareness and seek professional medical help and advice when needed.
Stages of Hypothermia
98.6F (37C)
Physiology:Walking and talking. All systems functioning
Cognition:Mentally sharp, paying attention to details, monitoring our environment, and responding appropriately.
Behavior: Physically coordinated,feeling strong and capable, making appropriate gear and clothing decisions, setting a pace appropriate for the conditions, eating and hydrating properly.
97F (36C)
Physiology: Brain functions slow.
The thermoregulatory center in the brain, sensing heat loss, will initiate several defensive actions.
It will vasoconstrict and reduce blood flow to the skin, creating an additional thermal layer to prevent further heat loss.
Piloerection occurs. That is when our hairs stand up on end to attempt to create an insulating of dead air space.
The rate of metabolism will increase, burning more glucose to produce heat.
Cognition: Judgment begins to fail.
We become more focused on the trail in front of us and less aware of the weather and our surroundings.
Enthusiasm wanes and apathy sets in.
Behavior: Protective instincts fade.
We don't make the best gear and clothing decisions. We don't make thee best food and hydration decisions. Our mood and reactions change and we become more withdrawn.
96F (35.5C)
Physiology: All systems are on full alert, and the body is doing everything possible to rewarm itself from the inside.
Shivering begins as a constant, uncontrollable, fine motor tremor, and is caused by opposing muscle groups acting against each other. Shivering produces heat, but it is wasteful exercise that doesn't produce useful work and interferes with activities that require precision: Lighting a stove, pulling a zipper, swinging and ice axe.
Decreased fine motor skills. We begin to lose dexterity and our speech begins to slur.
Metabolism increases to meet the new fuel demands.
Cognition: Mental abilities are falling rapidly. Decision-making, judgment, and “common sense” begin to fail. Self Preservation instinct are replaced with a “summit or bust” mentality.
Behavior: In the face of changing weather (e.g, Drop in temperature, Increase in wind). We may not take any construction action (.e.g putting on another layer). We may leave clothing or equipment behind.
94F (24.5C)
Physiology: Shivering is at its maximum, but other systems are slowing.
Metabolism is peaking, but fuel is being burned at such a furious rate(up to five times) that the stores will not last long(4-5 hours, rather than the typical 24) When the stores are used up the shivering will slow and eventually cease.
Cognition: We are not aware of being cold. We believe that we are thinking clearly, but we're not. Simple problem solving is impossible( we can't do basic addition/subtraction). When confronted with obvious problems, we may agree, but don't really care.
Behavior: Coordination fails, tripping and falling begins. We have trouble staying on the trail and easily become lost.
We don't take care of ourselves( if we lose a crampon or a mitten or get snow down our back , we don't do anything about it)
Still, we remain goal- oriented-onward to the top/end
92F (33.3C)
Physiology: Shivering become intense.
Cognition: Mentally, we are beginning to shut down. We enter a dream-like state where nothing seems real
Behavior: We're unable to walk though we may still be crawling toward the goal. Speech becomes very difficult.
90F (32.3C)
Physiology: Shivering becomes convulsive and begins to fail. Shivering is violent for a minute, then absent for a minuet. We are running out of fuel and energy and shivering will soon cease.
Cognition: We can still be aroused, and will try to answer questions, but our speech will be slurred, perhaps beyond recognition.
Behavior: Curling and mumbling. We adopt the fetal position( the body's last ditch effort to protect the core and minimize heat loss. As things deteriorate, we become less and less arousable, and as the final glucose stores are burned, our shivering mechanism begins to fail.
86F (30C)
Physiology: We become unconscious, ashen, and gray.
We enter a “Metabolic Icebox” (essentially suspended animation). All systems have slowed to minimize the consumption of oxygen and sugar.
The blood is 190% thicker than normal, Preventing a palpable pulse.
Heart sounds will be absent.
Respirations will slow to 3-6 per minute and so slow and shallow they may be impossible to detect.
We may appear dead: pulse less and breathless with cold, stiff skin and fixed pupils.
There is an expression for this situation.” a person is not dead until they are warm and dead”
Cognition: We are comatose and unresponsive to verbal or painful stimuli.
Behavior: We initiate no action.
