Changes

* '''[[Hypothermia]]'''. [[Hypothermia]] can occur when the temperatures are =Cold and Wet=When talking about running in the 50s if you are cold or exhausted, we have to look at how being wet changes things. See [[Hypothermia]] for details on this dangerous condition.* '''The 20 degree rule.''' A good approximation is to dress for temperatures that are 20 degrees Fahrenheit warmer than When the temperature is above freezing, we can become wet through the rain, but regardless of the actual temperaturewe can always become wet through our own sweat. So if it's 20 degrees out, dress Getting wet makes the cold worse for walking in 40 degrees. [[Perceived Temperature For Runners]] will give you a more accurate estimate. number of reasons:* '''Dress in layers.''' Layers will keep you warmer than a single layer, and allow for flexibility of removing some of your insulationBeing wet increases heat loss through evaporation.* '''Shed after warm-upWet clothing provides vastly less insulation than dry clothing.''' If practical, you Different materials can overdress for the first mile or so, until you warm uphave different residual insulation properties when wet. This requires you having somewhere * Your body regulates its temperature by blood flow to discard the extra clothesskin and by sweating. If you're wet, either through rain or a way of carrying them.* sweat soaked clothing, your body can'''If your hands are coldt control its temperature by sweating, wear a hatonly blood flow to the skin.''' This is an old boy scout saying, but it works. If you core temperature starts to drop, * Cold rain can directly reduce your body will protect your vital functions temperature by sacrificing carrying the heat away as it runs over your extremities, such as hands and feetbody.* '''If your hands are cold, wear =Common Mistakes=[[Arm Warmers]]File:RunningInTheCold.''' If you suffer from png|right|thumb|500px| A chart showing three possible temperature changes over time when running in the cold hands, then [[Arm Warmers.]] may be The chart above shows the key. If your arms are cold, ideal temperature changes include, and the blood flow to your hands is both chilled two common mistakes in blue and restrictedred. * '''Don't sweat throughThe green line represents the ideal temperature changes.''' If you wear too many clothes The runner starts off slightly cool, and sweat too much, you will sweat through your clotheswarms up during the first part of the run. Once your clothes are soakedthe runner has warmed up, you will become suddenly chilled. This means you will probably have they shared closing, or undue zippers to dress to be slightly cold, rather than toasty warmmaintain their temperature of the right level.* '''Windproof layers are a mixed blessing'''. A windproof layer will boost the insulation value of the underlying layersThe runner represented by the blue line warms up nicely, which can really help keep you warmbut does not shed sufficient clothing. Unfortunately As a windproof layer also stops result they sweat evaporatingexcessively, which regulates your temperature. This makes it much more likely that you will sweat though soaking wet clothing and become coldchilled. I use * The red line shows a windproof layerrunner that does not shed closing, but open and overheats. While it up as soon as I warm upis strange to think of heatstroke while running in the cold, then try to stay slightly coolit is possible. A windproof layer reasonably well trained runner is very useful likely to simply slow up and will perceive the heat stress as tiredness. This is because the subconscious responds to the rising core temperature by reducing muscle recruitment. However, an extra layeruntrained individual may raise their core temperature to rapidly, as it can be wrapped around and suffer heatstroke. =Staying Warm While Running in the cold=It's tricky to maintain the right temperature when running in the cold because your waist easily. I sweat will wear it until I warm up, then carry it in case I need some extra warmth later in reduce the runinsulation value of your clothing. There are several approaches you can take to overcome this.* '''Hydrate.Stop before you're cold'' Just because it's . A common approach is to be slightly overdressed, but to stop running before your sweat soaks your clothes to the point you get cold doesn't mean . This works well for shorter runs, but you doncan't need to drinkrun long distances this way. Use your thirst as a guide - for more on hydration see [[Practical Hydration]] and [[The Science Of Hydration]]* '''Try to stay dryChange clothes.''' Rain can chill you very quicklyThis requires some logistics, so in cooler conditions, you need some rain protectionbut it's possible to change clothes as each set becomes soaked. More on this in [[Running in the Rain]].* * '''Your lungs are fine.Stay dry''' Your lungs will not freeze, not even at -40 degrees. Your lungs may get irritated by Staying dry while running in the low humidity, but they will get used cold is harder than it sounds. You either have to avoid sweating or make sure thatall the sweat evaporates before it builds up and soaks your clothing. It This can work in mild conditions where you are wearing thin thermal layers that allow for good sweat evaporation, but as you put on more clothing, the harder it is possible for the sweat to get exercised induced asthmaevaporate. For some runners, which is a narrowing especially smaller and slower runners, it's possible to run and not sweat much, but for most of the airways when exercisingus, running results in high sweat rates. If you suspect you have this condition, seek medical advice.* it's raining, it'''No cotton.''' This is true for s hard to stay dry as any conditions, but worth restating herewaterproof layer you wear will prevent your sweat from evaporating. Wear clothes made from synthetic(Breathable waterproof material rarely keeps up with the high sweat rates of runners, wicking fibers, such as CoolMaxand ironically the breathability drops dramatically when the outside of the material is wet.)* '''Watch for frostbiteWetsuit.''' Your extremities may go numb early in your run, but they should The wet suit approach is to wear sufficient layers to be warm upeven when soaking wet. Anything that stays numb needs to be checked.* This can work reasonably well, and it'''Watch for ices often the only viable approach in cold rain.''' Slipping on ice This approach causes your clothing to become heavy with water, but there is a wide variation in how different clothing behaves when soaking wet. Having your skin immersed in cold water can pull cause problems with maceration (the prune effect), including chaffing, [[MuscleBlister Prevention|musclesblistering]] or cause falls, immersion injuries and chilblains. You In cold rain it can get [[Traction Aids]] be important to have a waterproof layer; this is not to attach keep you dry, but to prevent the cold rain from washing over your [[Shoes]] if ice is a significant problem. See [[Traction Aids]] for more detailsskin and chilling you. * '''Hat and glovesDouble waterproofs.''' These are important While it's not possible to keep you warmdry, but they can also be taken off and tucked in a waist band easily. This allows you it is possible to adjust keep your insulation for the conditionsclothing dry. I like gloves This approach uses four layers of clothing. The first is a base layer that convert into mittens (more on these in a future blog)* '''Vaselinekeeps your soaking skin somewhat comfortable.''' If you are still having problems with Next there is the first waterproof layer that prevents your hands and feet, spreading Vaseline over them before putting on your socks or gloves will dramatically improve insulating clothing from getting soaked from the insulationinside by sweat. It's a bit strange The third layer is the first time you do itinsulation, but it works very wellwhich may actually consist of multiple thin layers of insulating clothing.* '''SunglassesFinally there is a second waterproof layer that keeps the rain from soaking the insulation from the outside.''' Keeping your eyes protected can help you keep This is a little warmerdifficult combination to get right, and reduce how runny as you do not have the ability to regulate your nose getstemperature through sweating. I use Oakley sunglasses with interchangeable lensesTherefore the risk of heatstroke is quite high, so I can use clear glass when it's darkbe careful.* =General Tips=# '''Chemical WarmersThe 20 degree rule.'''A good approximation is to dress for temperatures that are 20 degrees Fahrenheit warmer than the actual temperature. Using chemical warmers can help keep So if it's 20 degrees out, dress for walking in 40 degrees. ## The faster your hands from getting too cold. I find these seem to not only keep my hands warmrun, the more heat you generate, but also provide some extra warmth to so the rest of my body and a little phycological boostless insulation you need. You can warm The same temperature will feel different to different runners based on their height, weight and pace. ## This is a simplified rule, and the packs with details depend on pace, height and weight; [[Perceived Temperature For Runners]] will give you a hairdryer to get them extra warm (Thanks to Megan H)more accurate estimate. ** You can also save the hand warmers for another run by putting them in a sealed bag with the air squeezed out. (Thanks Charles/Kristine)* # '''Don't sweat through.''''Neck Warmer.''' A fleece neck warmer can protect If you wear too many clothes and sweat too much, you will sweat through your face and neck from the coldclothes. I use a Turtle Fur neck warmer ([http://wwwOnce your clothes are soaked, you will become suddenly chilled.rei# '''Stay Cool'''.com/product/663041 http://wwwTo avoid excessive sweating, you should aim to feel slightly cool, rather than comfortably warm.rei.com/product/663041]).* Don't get so cold that you shiver, but it's okay to feel chilly. # '''Warm Up InsideHydrate.'''Even in cold weather hydration is important. Often the first mile or so is the worst, Use your thirst as your body has not started to produce sufficient heat to offset the cold. Warming up a guide and for 10 minutes inside, by running up and down stairs, doing a jump rope, or using a more on hydration see [[Practical Hydration]] and [[Treadmill|treadmillHydration 101]]. (Thanks to Melanie M for this tip)* # '''Numbness is bad.'Start into the wind'''. If it's windy, start Your extremities may go numb early in your run into the wind so that on the way back, you won't freeze due to sweatingbut they should warm up. (Thanks Anything that stays numb needs to Bobby A for be checked as this tip)* ''can result in frostbite or other cold injuries. Beware anything that restricts circulation, such as elastic cuffs, as the reduced blood flow can contribute to frostbite.# '''Suck then blowWatch for ice.'''Slipping on ice can pull muscles or cause falls. If you have You can get traction aids to attach to your shoes if ice is a significant problem with the tube on your hydration bladder freezing up, blow air back down the tube each time you have finished drinking. The drink is unlikely to freeze in the bladder itselfSee [[Traction Aids]] for more details. # '''Emergency trash bag'''. If things go badly, a trash bag can help keep you warmer, but the tube is very hard especially if you have to keep warmstop running. Insulation around the tube helps You can fold a bit, but not enoughtrash bag up quite small and tuck it in your waistband. (Thanks to Ron Bowman for this tip)* ==Clothing==# '''Ski GogglesAdjust Your Clothing. '''It is of most importance that you adjust the amount of insulation you get from your clothing as the conditions change. Below -10f/-23c wear ski goggles or other eye protection Trying to stop make sure that your eyelashes freezing togetherclothing is as flexible as possible. Even in moderately cold conditions, eye protection can help keep you warmer and reduce the amount # '''Zippers are your nose runsfriend. * '''Windproof underwearAnd one of the best ways of adjusting the insulation you get from your clothing is to have zippers.'''. For men, wearing underwear with a windproof front can provide vital protection.* '''Protect Zippers on jackets and clothing allow you to quickly and adjust the amount of insulation to the frontconditions, and they can provide a fine grained adjustments.# '''Dress in layers. Wearing tights and top that are thicker ''' Layers will keep you warmer than a single layer, and/or windproof on the front provide warmth while preventing overheating. The [http://www.golite.com/Product/ProdDetail.aspx?p=AM1352|Go Lie Black Mountain] jacket is excellent. allow for flexibility of removing some of your insulation. * # '''Emergency trash bagStrip off after warm-up.'''. If things go badlypractical, a trash bag you can help keep you warmeroverdress for the first mile or so, especially if until you have to stop runningwarm up. This requires you having somewhere to discard the extra clothes, or a way of carrying them. An alternative is to have clothing with zippers so you can reduce your insulation. * # '''Cover gapsWindproof layers are a mixed blessing'''. Below 0f/-18cA windproof layer will boost the insulation value of the underlying layers, it is critical to ensure there are no gaps or exposed skinwhich can really help keep you warm. Unfortunately a windproof layer also stops sweat evaporating, which regulates your temperature. The phrase 'exposed skin freezes in minutes' should This makes it much more likely that you will sweat though and become cold. I use a windproof layer, but open it up as soon as I warm up, then try to stay slightly cool. A windproof layer is very useful as an extra layer, as it can be taken wrapped around your waist easily. I will wear it until I warm up, then carry it in case I need some extra warmth later in the run. # '''Base layer'''. I recommend a close fitting, very thin base layer. The goal of this base layer is not to provide insulation, but to spread out the sweat, and prevent chafing. I typically run in an [[UnderArmour HeatGear Top]].# '''Hat and gloves.''' These are important to keep you warm, but they can also be taken off and tucked in a waist band easily. This allows you to adjust your insulation for the conditions. # '''Windproof underwear'''. For men, wearing underwear with a windproof front can provide vital protection. # '''Protect the front'''. Wearing tights and top that are thicker and/or windproof on the front provide warmth while preventing overheating. The [http://www.golite.com/Mens-Black-Mountain-Thermal-Wind-Jacket-P46654.aspx Go Lite Black Mountain jacket] is excellent. # '''No cotton.''' This is true for any conditions, but worth restating here. Wear clothes made from synthetic, wicking fibers, such as CoolMax. # '''Wet insulation'''. Different materials can have very different characteristics when they are wet.## '''Insulation when soaked'''. Some materials are much warmer when they are completely soaked. Wool has a reputation of being one of the better materials for retaining warmth when wet. However any soaking wet material will cause you to lose heat through evaporation unless there is a windproof layer over the top.## '''Weight when soaked'''. I've found that some synthetic tops become surprisingly heavy when soaking wet. I don't know of any way of predicting this behavior other than trying it out.## '''Breathability. '''Some thermal layers will breathe well and allow sweat to evaporate before the government is soaked. This is good, as it allows your body to control its temperature through sweat affectively. Other materials do not breed so well and so the sweat will not evaporate until the government is completely soaked, at which point your temperature is likely to drop rapidly.# '''Neck Warmer.''' A fleece neck warmer can protect your face and neck from the cold. I use a Turtle Fur neck warmer ([http://www.rei.com/product/663041 http://www.rei.com/product/663041]). # '''Sunglasses.''' Keeping your eyes protected can help you keep a little warmer, and reduce how runny your nose gets. I use [http://www.amazon.com/Oakley-Half-Jacket-2-0-Sunglasses/dp/B007EN0FL0 Oakley Half Jacket sunglasses] with interchangeable lenses, so I can use clear glass when it's dark, or the cheaper and more convenient [http://www.amazon.com/Tifosi-Tyrant-Sunglasses-Gunmetal-Fototec/dp/B002Q1F1AA Tifosi Tyrant sunglasses] that have photochromic lenses that go nearly clear in dark conditions.  ==Cold hands or feet==# '''If your hands are cold, wear a hat.''' This is an old boy scout saying, but it works. If you core temperature starts to drop, your body will protect your vital functions by sacrificing your extremities, such as hands and feet. However, this is a delicate balancing act, as you need to stay cool enough that you are not sweating excessively.# '''If your hands are cold, wear arm warmers.''' If you suffer from cold hands, then [[Arm Warmers]] may be the key. If your arms are cold, the blood flow to your hands is both chilled and restricted. # '''Chemical Warmers'''. Using chemical warmers can help keep your hands from getting too cold. I find these seem to not only keep my hands warm, but also provide some extra warmth to the rest of my body and a little physiological boost. You can warm the packs with a hairdryer to get them extra warm (Thanks to Megan H). You can also save the hand warmers for another run by putting them in a sealed bag with the air squeezed out. (Thanks Charles/Kristine).# '''Vaseline.''' If you are still having problems with your hands and feet, spreading Vaseline over them before putting on your socks or gloves will dramatically improve the insulation. It's a bit strange the first time you do it, but it works very well. # '''Convertible Mittens'''. I've found that the gloves that include a cover to convert them into mittens work remarkably well. My favorites are the [http://www.amazon.com/Saucony-Womens-Ulti-Mitt-Large-Vizipro/dp/B006ZW6L4Q Saucony Ulti-Mitt].  ==Extreme Cold==# '''Your lungs are fine.''' Your lungs will not freeze, not even at -40f/-40c. Your lungs may get irritated by the low humidity, but they will get used to that. (It is possible to get exercised induced asthma, which is a narrowing of the airways when exercising. If you suspect you have this condition, seek medical advice.)# '''Suck then blow'''. If you have a problem with the tube on your hydration bladder freezing up, blow air back down the tube each time you have finished drinking. The drink is unlikely to freeze in the bladder itself, but the tube is very hard to keep warm. Insulation around the tube helps a bit, but not enough. (Thanks to Ron Bowman for this tip) # '''Ski Goggles'''. Below -10f/-23c wear ski goggles or other eye protection to stop your eyelashes freezing together. Even in moderately cold conditions, eye protection can help keep you warmer and reduce the amount your nose runs. # '''Cover gaps'''. Below 0f/-18c, it is critical to ensure there are no gaps or exposed skin. The phrase 'exposed skin freezes in minutes' should be taken seriously. # '''Warm Up Inside'''. Often the first mile or so is the worst, as your body has not started to produce sufficient heat to offset the cold. Warming up for 10 minutes inside, by running up and down stairs, doing a jump rope, or using a [[Treadmill]]. (Thanks to Melanie M for this tip) # '''Start into the wind'''. If it's windy, start your run into the wind so that on the way back, you won't freeze due to sweating. (Thanks to Bobby A for this tip)   =Cold Injuries=There are four main cold injuries you need to consider as a runner.  ==Hypothermia ==''Main article: [[Hypothermia]]'' Hypothermia is the obvious and most serious problem, which is when your core body temperature drops. Hypothermia can kill and can occur in relatively mild conditions. There are several ways runners are likely to get hypothermia:* Probably the most common is when a runner does not adjust their clothing and sweats through. Once their clothing is saturated, they rapidly become chilled. This can occur relatively quickly, especially when the sweat reaches the surface.* A sudden downpour can rapidly chill a runner. The rain can saturate clothing which reduces its insulation, and heavy rain can wash over the skin taking heat with it.* A runner may be appropriately dressed while running, but should they be forced to stop, they can become rapidly hypothermic.* A sudden change in weather conditions can occur. Typically this is an increase in wind speed, or the drop in temperature that occurs at sunset.Shivering is the first warning sign of hypothermia. If you are shivering, you should do something to remedy the situation:* If you've stopped running, and are able to start again, then do so.* If you can put on more clothes, or zip up/tuck in the clothes you have, then do so.* If neither of these options is available to you, then try to seek shelter as quickly as possible.Another symptom of hypothermia is the "umbles" – stumbles, grumbles, mumbles. This is because mental functioning declines with hypothermia, which also results in a decline in the ability to make good decisions. Watch out for those around you the symptoms of hypothermia.  ==Frostbite ==Frostbite is when your flesh becomes frozen and can lead to permanent damage. The signs of frostbite are numbness, waxy or unusually firm skin, but often the victim of frostbite is not aware of the problem until too late. * Maintain circulation.** Reduced circulation is a key risk factor for frostbite, so avoid any constricting shoes, clothing or jewelry.** Stay warm as your body will reduce circulation to your extremities to preserve your core temperature.** Avoid dehydration, as this may reduce circulation.** Be especially careful if you are on medication or you have a medical condition that reduces circulation.* Protection from the cold.** It is important to protect your extremities, especially under severely cold conditions. Even without wind, exposed skin can become frostbitten in 30 min. when the temperature is -15c/5f. (See the chart below for more details.)* Treatment.** If you suspect frostbite, you should seek professional medical help. ** Do not attempt to re-warm a frostbitten extremity unless definitive medical care is more than two hours away.[[File:windchill.gif|frame|NOAA frostbite risk chart.]]For more details, read [http://www.wildmedcenter.com/uploads/5/9/8/2/5982510/wms_frostbite.pdf Wilderness Medical Society Practice Guidelines for the Prevention and Treatment of Frostbite]. ==Immersion injury ==Immersion injury occurs when your skin has been soaked in cold water for long periods of time (hours). Immersion injury occurs in water temperatures between 59f/15c and 32f/0c. This is different to frostbite because the skin is not actually frozen, but there is still cold damage to the cells. (Immersion injury is sometimes called trench foot.) ==Chilblains ==Chilblains are damage to the skin from rapid warming. Typically the conditions that cause chilblains are similar to immersion injury, but the damage of chilblains can be reduced by slow warming. (There is some degree of genetic predisposition to chilblains.) After a long run in cold conditions, it is best to allow your skin to come back to normal temperatures slowly, rather than jumping into a hot shower. If you do reform your skin too rapidly, you may get a burning itching sensation over the affected skin, or in extreme cases blistering. I've found that turning the shower as cold as it will go can help reduce the burning and itching, but that's thoroughly unpleasant when you're feeling chilled after a long cold run.