Hypothermia & Layers to Keep You Warm

Although the winter season is almost over, many areas of the country are still dealing with arctic temperatures.  Snow, sleet, freezing rain and hypothermia are factors we must deal with.  As police officers we have several things to consider when getting dressed for duty during the winter: 1) are we sufficiently protected from the elements and temperature? 2) is our equipment easily accessible? and 3) are we in compliance with department policy?

First I want to address department policy.  If you were to look at department policies from across the country, you would find policies that would fill a one inch binder up to several three inch binders and some have even more, which I’ve seen.  Hopefully, your department took the seasonal weather into consideration when they wrote, and do revisions to, the policy.  Some of the policies run the gamut from being very strict to very lax or vague.  Do your best to dress within policy; I know it isn’t easy sometimes.

Keeping department policy in mind, how should we dress?  We have all heard about dressing in layers, but there are good and bad layers.  Wearing one or more layers is up to you, but should be based on the conditions you will be working in.

Cotton is soft, flexible and comfortable, but for layering in the winter, it IS NOT a good option.  Why is cotton bad?  Cotton is notorious for holding moisture, which is really bad when you are out in the cold.  Generally we have the heater blasting in the cruiser, and if you don’t watch it, then you start sweating and then get cold even faster when you get out of that nice warm cruiser and into that frigid air.  Even if you don’t start to sweat, the insulating properties of cotton just are not there to keep you warm.  I have a friend that isn’t a LEO, but works outside all day long that will put on five plus layers to stay warm, but they are all cotton layers and then complains to anyone that will listen that he is cold.

Here is my suggestion for what to wear for upper and lower body.  The innermost layer should be a silk, polypropylene or similar material.  This layer is available in variable weights and will provide some insulation, but the primary purpose is to wick moisture (sweat) away from the body.  If the need is there to wear an additional layer, then it should be a wool or polyester (fleece) material.  This layer is designed insulate you by trapping air and to absorb moisture and transport it (the moisture) outward.  If you are wearing concealable body armor, it would now go on and then the uniform shirt.  If your department allows you to, you could then wear a uniform sweater. Personally, I wear my body armor in an external carrier, which I find more comfortable year round.

Jackets are another layer to take into consideration.  When choosing a jacket, it should be a coated nylon or breathable fabric that is water and windproof.  Coated nylon isn’t moisture wicking, whereas breathable fabrics are, but both provide water and wind protection.  I have an all-weather jacket that is breathable and is wind/waterproof.  It also incorporates a removable fleece liner jacket with zip-off sleeves.  The fleece liner jacket can be worn by itself during other parts of the year, with or without the sleeves.  The main jacket can be worn with or without the liner jacket.  During the spring and fall, I generally wear it without the liner jacket.

Jackets of this type can cause you to get very warm if incorporated with multiple layers, so make sure you don’t get overheated, especially in the cruiser.  If given the option, I don’t like wearing jackets while on-duty and I will discuss that in the next section.  I prefer to wear a few layers, and only wear my jacket, without the liner jacket, when needed for wind, snow and rain protection.

Three last things to cover: head, hands and feet.  As far as your head protection goes, there is nothing wrong with a knit watch cap (beanie), except it may not provide wind or water protection.  I like wearing a pull-over hood (balaclava).  They are pretty universal in that they can be folded up and used like a beanie, pulled down covering entire head and face except the eyes, or pulled down further to just protect the neck.  Some departments frown upon these because they make you look evil or something… whatever.

Hand protection is kind of touchy.  We all know how irritable we can get when our hands get cold, so make sure you get gloves that you are comfortable with and provide some cold weather protection.  The main thing to remember is that the gloves must be thin enough to still operation your firearm, handcuffs, radio etc.  Those thick ski gloves do you no good if you can’t operate your equipment.

Your feet are like your hands: if your feet are cold, you are miserable.  Waterproof and insulated footwear - preferably boots - are a must.  Do yourself a favor and don’t get just a waterproof boot, because you will end up wearing more socks to keep those little piggies warm.  I also suggest that you look for a boot that is designed and marketed as a winter boot.  Boots designed for the winter typically have a softer rubber sole, which will remain more flexible when the temperature gets real frigid.  It is a good idea to wear a pair of decent quality wool socks.  Also available are silk and polypropylene type socks that are moisture wicking like the inner layer discussed above.  It is bad enough when your feet get cold, but if they are sweaty and then get cold, it is even worse.

All of the layers discussed above are very important, but I believe the inner moisture wicking layer to be most important.  Water conducts heat from your body about 25 times faster than air at the same temperature.  So if you are not wearing a moisture wicking layer, such as cotton, you are trapping that moisture against your body, which in turn will lower your temperature faster, which can lead to hypothermia. Remember, we sweat to COOL our bodies; that’s not good if temperatures are already cold and we need to maintain body heat.

WebMD defines hypothermia as “a potentially dangerous drop in body temperature, usually caused by prolonged exposure to cold temperatures”.  The common person has a body core temperature of 98.6° Fahrenheit (F).  Hypothermia typically will start to set in when the core temperature drops below 95.0° F.  Recently, trauma medics have realized and are now actively teaching, that if the body’s core temperature drops below 90° F then mortality is 100%.  Read that again: If your core temperature gets below 90° F you will die and, to date, resuscitation efforts on such victims has shown zero success.

There are two types of hypothermia: chronic and acute.  What most people experience is chronic hypothermia and is from a prolonged exposure to the elements.  Acute is from a sudden immersion into cold water; hopefully none of you experience that.

There are a few factors that influence heat loss which can lead to hypothermia.  The older you are the faster you lose heat. I don’t understand it, but that’s the way it is.  Those that are thin lose body heat faster than heavier people (body fat IS an insulator).  Medical conditions such as injury, illness, shock, etc. can lead to fast heat loss.

There are three stages of hypothermia, so take note of and remember this.

1)      Shivering, impairment of movement and cold skin are signs of mild hypothermia.

2)      Poor coordination, confusion, apathy and slurred speech are signs of moderate hypothermia.

3)      Signs of severe hypothermia are slow respiration and pulse, muscular rigidity, diluted pupils, coma and death.

Depending on the number and thickness of the layers you wear, you may need to go up in uniform size.  With the added layer thicknesses, you will be adding bulk which can hinder flexibility.  A couple of things to keep in mind, when adding layers:

• Make sure they are not tight fitting layers.  As you add tight fitting layers, it drastically reduces your flexibility, which reduces the mobility of your arms and legs.  That makes it difficult to run, jump, and fight.  I mentioned before having to possibly get a larger size uniform; that is to allow sufficient flexibility and mobility.  While in your everyday civilian clothes, try crouching down like a catcher, swing your arms around, see how much flexibility you have.  Now do this again with all the layers, body armor and uniform on.  The goal is to have the added layers of protection, but maintaining as close to if not the same amount of flexibility.
• I mentioned before that I don’t like wearing jackets while on duty, and I know a lot of officers don’t.  For me it is a matter of comfort and the jacket getting in the way of my equipment.  Yes, my jacket has the side-zip opening for my firearm, but as we all know, deadly force isn’t the only force option.  I have practiced going for my Taser®, handcuffs, radio, spare mags, etc. while wearing my jacket, but I just don’t like it.  So, I keep my jacket in the cruiser and will put it on when needed.  I have even seen officers tuck their jackets into their pants, but I find that very uncomfortable.

I hope this information helps you stay warm for the remainder of this winter and future winters.

Stay Safe!