How To Prevent Illness by Breathing Cold Air
Have You Ever Suffered Serious Hypothermia or Frostbite?
Entering the Cold
Stepping outside, from a warm home, into temperatures below 0°C and colder, can cause a shock to the body, especially to the heart.
The heart tries to compensate heat loss caused by convection and transpiration, but also heat loss caused by evaporation of moisture through the lungs.
A weak heart can fail under this instant demand for labour. Extreme sporters always protect themselves against heat loss through respiration in very low temperatures.
You can protect yourself against cold with good warm clothing to minimize radiation, but you cannot easily protect against evaporation and heat loss through the lungs.
Respiration always continues and increases with the amount of labour. At least 25% of all body heat loss and at least 35% of all water loss goes through the lungs.
During rest, a human has a respiratory rate of between 600 to 900 times per hour, replacing with every breath at least 0.5 litre of air. Experts call this the tidal volume. Both frequency and volume increase with the amount of labour.
The inhaled air travels through nose and mouth into the lungs. The body has to work to heat this cold air to body temperature in the first step. In the second step the fresh heated dry air in the lungs will force the body to evaporate water from the body into the fresh, just warmed dry air. Evaporation extracts the most energy from the body.
Humans are unlike most animals unadapted to extreme cold.
This balaclava is currently one of the best types money can buy. The resistance of the respirator is relatively low, while the efficiency of heat extraction is high. This mask is even suitable for sports and cold storage workers. The amount of saved energy is high enough to prevent hypothermia in wild life situations.
Volume (in order of volume)
Expiratory reserve volume
Functional residual capacity
Inspiratory reserve volume
Total lung capacity
Respiratory Volumes of an Average Human Being
Amount of Heat and Water Loss
Under normal conditions at temperature of -10°C (respiratory activity is slightly increased, like walking) the human body loses approximately 110kJ/hour through respiration. This heat loss consists of heating of 1000 litre of air from -10°C to 37°C and the evaporation of about 25 grams of water.
110kJ/hour is equivalent to 3 grams of fat. The loss of water can be more critical on the short term.
Respiratory heat loss through labour or sports can easily run up to 1200kJ/hour.
When stranded in extreme cold the human body can easily loose 0.5 kg of pure fat per day through unprotected respiration. This is equivalent to a few good meals.
The loss of water through respiration can be life threatening as well. At least 0.6 litre of water is lost through respiration per day. Fatigue and hypothermia is very easy to catch under these conditions.
Protection of the respiration in harsh conditions can make the difference between life and death. Especially when you're stranded, the balance is fragile.
Most animals are equipped with the so called 'rete mirabile' or wonderful net that protects the body from overheating, and also protects the heart and lungs from damage due to the respiration of cold air. Humans have a limited pre-heating system to warm up the inhaled air before it enters the lungs. The heating capacity of the nose and mucous membranes is very limited.
Too much respiration of cold air can cause numerous of unwanted effects, like creation of histamine in the lungs, shivering, dehydration, frostbite and hypothermia.
Hypothermia catches its victim nearly unnoticed, while the core temperature of a person is dropping. This process can take place with an amazing speed. Hypothermia runs in multiple stages from light shivering up to death.
Ways to Protect Yourself
There are a few ways to protect your respiration against the cold
- Scarf - The biggest disadvantage of the scarf is that the textile gets wet. Parts of the scarf will freeze and parts will get wet. Part of the exhaled air passes along the nose upwards, leaving condensation on the skin around the eyes. Or in the case you're wearing glasses, condensation on the glasses. A scarf is uncomfortable to wear, and is a typical 'have-nothing-better' option. The risk of frostbite in the face because of the condensation is very large.
- Balaclavas - There are a few manufacturers of balaclavas with a respirator attached inside the mask. The breathing resistance of these respirators is too large to give a comfortable respiration in all conditions. Compared with unprotected respiration this masks feel a lot better, but it are still poor developed variants with low efficiency of around 30%. Heat and moist loss is still very high.
- Eskimask (working title) - A new patented respirator with a hardly noticeable resistance and with an efficiency of around 80%. Heat and moist loss through respiration are also reduced to around 80%. The mask consists of a special labyrinth that allows air to pass easily while catching all available energy. The masks are thoroughly tested on Svalbard (Spitsbergen) under inhumane conditions down to -50°C. The mask is also able to protect respiration against hot air. Pictures are not yet available and the masks are not yet for sale.
Adhoc made Balaclavas already exist as long as humans try protect themselves against extreme cold. Professional balaclavas to protect respiration against extreme cold appeared a few years ago as the better variants of the adhoc variants.
With every exhale the warm moisty air passes the relative cold heat exchanger, which gets warmed up again by the warm exhaled air. The moist in the exhaled air condensates on the heat exchanger. How much moist condensates depends on the efficiency of the heat exchanger.
When again inhaling, the cold dry air passes the warm moisty labyrinth of the heat exchanger. The air that enters the lungs is warmer and moister than it would bee without heat exchanger. Lungs and heart have to work much less, and the body energy is saved for other tasks.
How High are the Risks?
Annually around 1 billion people are exposed 5 days or more to temperatures below 0°C. Mortality rates during these period doubles compared to mortality rates during periods of median temperatures.
This mortality rate is directly connected with hypothermia, and heart attacks due to low temperatures.
When temperatures drop below -10°C especially in area's where people are not used to this, the risk to catch hypothermia or a heart attack increases by a factor of 30!
Every Car and Airplane should be Equipped
Every car and airplane should be equipped with an Eskimask.
Especially when the vehicle or airplanes gets stranded, this equipment saves as much energy per day as one good meal.
The Eskimask can also be equipped with charcoal filters against poisonous gases.
Working Both Ways
Heat exchangers can work both ways, as long as the construction doesn't melt, or the condensate doesn't freeze. Cold air is warmed and hot air is cooled.
The Eskimask keeps working in extreme temperature down to -60°C. Some parts of the heat exchanger can start to freeze, but due to the construction the main part stays open for heat exchanging.
In extreme hot situations up to 200°C, the Eskimask cools the inhaled air and makes it possible to keep breathing. Especially when the Eskimask is equipped with an active charcoal filter, it is possible to survive situations that are normally lethal.
Every car, air plane and building should be equipped with an Eskimask in case the air becomes dangerous to breath.
Made from Special Alloy, a Unique Construction
The Eskimask extracts nearly all energy from the exhaled air, while it passes the heat exchanger. This requires an extraordinary construction. In the same time the heat exchanger must be light and able to store the extracted energy, enough to warm cold air or to cool down hot air. The surface of the labyrinth is 0.3 m2, enough to extract energy from exhaled air in an instant and to store this temporarily for the next inhale.
The construction is designed after a long study on air flow, heat exchanging and production techniques. The heat exchanger consists of aeroplane aluminium coil which is highly resistant against corrosion.
The heat exchanger is mounted in an universal housing, which makes it possible to exchange it to different kinds of face masks.
© 2013 by Buildreps