Sunday, March 29, 2020

COVID-19, And A Simple, Homemade Respiratory Mask ©

When it Comes to Survival, Get Some Rest! ©


 
Photograph by the author.

I started writing this article more than a month ago, at that time COVID-19 was only in Wuhan, China.  Now, obviously it’s everywhere.  And while the main thrust of this article is about what to do if you are “misplaced” in the wilderness, today many, many people are anxious and suffering from sleepless nights, because of the corona virus.  Getting plenty of rest, so you can control your fears and anxieties is important in any crisis, whether you are turned around in the woods or dealing with a virus – Author’s note.

Count Rugen to Prince Humperdinck, in the Princess Bride, 19871

Princess Bride!”, you say, “That’s a romantic fantasy from the 80s!  What does that have that have to do with survival and woodlore?  Yes, this is a quote from a romantic fantasy movie, but the advice to “get some rest” is actually very good survival advice.  But, it’s okay to miss some sleep,” you think, “it’s no big deal, I can sleep after I’m rescued, right?  Wrong!  Read on to find out why...

 
An excerpt from, Major Stephen J. Townsend’s The Factors Of Soldier's Load, page 56.  This quote was originally found in Brigadier General, S. L. A. Marshall’s, The Soldier’s Load and the Mobility of a Nation.

Fatigue and fear, fear and fatigue, a deadly spiral.  Being tired or fatigued makes it difficult to control your fears and being afraid can cause you to become more tired or fatigued (for more on fear and survival read “What Are You Scared Of?! ©”, HERE).  But just why are your tired and fatigued?  Perhaps, it is muscular fatigue caused by overexertion or over-exercise, the inevitable consequence of performing important and necessary physical survival tasks, such as lifting, carrying, walking, etc.  Perhaps you are mentally fatigued, because of your psychological reaction to the “Seven Enemies of Survival”: cold, thirst, hunger, boredom, loneliness, pain and fatigue.  Don’t forget that being fatigued, mentally or physically, will make you increasingly more tired and fatigued, over time, as you struggle with this and the other enemies of survival.  The only way to recover from fatigue is to rest.  But what if you haven’t been sleeping? 


The Rule of Threes, graphic by the author.


Just as, on average, you can’t live longer than three days without water; you can’t live more than three days without sleep.  But” you say, “that 17-year-old kid, Randy Gardner went without sleeping for 264 hours, almost 11 days, back in 1965!  Your right he did, at a school science fair, all-in-all a pretty tame place.  By the end of his record setting ordeal, Randy Gardner, although awake, was cognitively dysfunctional2.  Would he have been able to stay awake for 264 hours in the middle of the wilderness, without hallucinating, falling, accidentally getting wet and hypothermic, hurting himself, etc., I don’t think so, and here is why. 

An excerpt from “Sleep Deprivation Is The Same As Being Drunk, Study Says”, by Kristina Rodulfo

According to current studies, going without sleep affects the body in the same way as drinking alcohol does.  Even moderate sleep deprivation impairs your alertness, your memory and your motor performance and precision.  In fact, after only 17 to 19 hours without sleep, you will perform as if your blood alcohol concentration (BAC) was 0.08%, which is considered impaired by US law.  For the average sized American woman, this would mean drinking three standard drinks in an hour, and for the average sized American man, it would take drinking four standard drinks in an hour, to reach a BAC of 0.08%3.
  

An excerpt from On Combat, by Lt. Col. Dave Grossman and Loren W. Christensen, page 24, showing the effects of not sleeping on performance.

The US Army performed a study, shown above, which underscored how going without sleep will affect you the same way as drinking alcohol does.  This study documented a drastic drop off in performance and efficiency as the amount of sleep declined.  In this study Groups Two, Three and Four were kept awake between 18 and 20 hours each day for 20 days.  During this experiment their performance dropped to only 15%, for Group Four, and to 50%, for Group Two, of their peak task efficiency: in effect they performed the same as if they had been drinking and had a blood alcohol concentration (BAC) of 0.08%!

Now, many people go without sleeping for 24 hours, it isn’t that uncommon.  However, not sleeping for more than 24 hours will affect you the same way as if your blood alcohol concentration is at 0.10%, the equivalent of four standard alcoholic drinks.  And the effects of not sleeping get progressively worse after 24 hours.  In fact, as Healthline.com notes, the effects of going without sleep for more than 24 hours include, drowsiness, irritability, impaired decision-making and judgement, impaired hearing and vision, decreased hand-eye coordination, increased muscle tension and tremors.  In addition, you might begin to experience altered perceptions or hallucinations and memory deficits.  All these combined, increase your risk of having an accident, and in the wilderness, just as on the highway, an accident can be fatal.  The only good news is these symptoms will all go away once you have had some sleep.

After just 36 hours without sleep, only a day and a half, according to Healthline.com, you can expect to suffer from hormonal imbalances, which can alter your appetite, metabolism, temperature, mood and ability to deal with stress.  Additionally, you will be prone to making risky decisions, have inflexible reasoning, a decreased ability to pay attention, a lack of motivation and a difficult time speaking and choosing words.

After 48 hours, or two days, without sleeping you will begin to experience “microsleeps”, which are involuntary naps where your brain will shut down, lapsing into a trance like state that might last from 15 to 30 seconds. 

And finally, after 72 hours, or three days, without sleep, Healthline.com reports that on top of all the previous symptoms you will have an increased difficulty thinking, multitasking and remembering.  You might also experience hallucinations, where you see things that aren’t there.

In a wilderness survival situation, would you drink until you were drunk?  No, of course not!  But if you don’t sleep, that is exactly what you are doing.  And hallucinating and seeing things that aren’t there can seriously impact your chances of surviving a wilderness emergency, so...

An excerpt from the 1969 edition of Survival Training Edition, AF Manual 64-3, page 1-134.
  
So, work smarter not harder and when you can rest, REST!  If all your immediate survival needs are met, take a nap, sleep!  Sleeping will lower your metabolism, helping you to conserve vital and scarce energy, it will decrease you level of fatigue, helping you to think more clearly and control fear, and it will increase your task efficiency when you are performing critical survival chores. 

An excerpt from the 1969 edition of Survival Training Edition, AF Manual 64-3, page 1-13.



Remember “...fatigue is an enemy of survival.  Try to set up a program of rest.” a quote and an excerpt from the 1969 edition of Survival Training Edition, AF Manual 64-3, page 1-14.
   
So, if you become tired, either when you have become physically or mentally fatigued, rest, take a nap!  Remember Count Rugen’s advice “Get some rest.  If you haven’t got your health, then you haven’t got anything.

I hope that you continue to enjoy The Woodsman’s Journal Online and look for me on YouTube at Bandanaman Productions for other related videos, HERE.  Don’t forget to follow me on both The Woodsman’s Journal Online, HERE, and subscribe to BandanaMan Productions on YouTube.  If you have questions, as always, feel free to leave a comment on either site.  I announce new articles on Facebook at Eric Reynolds, on Instagram at bandanamanaproductions, and on VK at Eric Reynolds, so watch for me.

That is all for now, and as always, until next time, Happy Trails!


Notes


1 From the movie, Princess Bride, 1987, 20th Century Fox.  I am aware that if you can quote most of the movie from memory that you are kinda a geek, however in my defense and as someone who has studied fencing, sword fighting and stick-fighting for more than 30 years; the sword fighting is exceptional and the sword masters that they talk about while fighting at the top of the Cliffs of Insanity were real swordsmen, whose writings I have studied.

2 J. Christian Gillin, “How Long Can Humans Stay Awake?”

3 In the United States, the term “standard drink” refers to a drink which contains enough alcohol to raise an average person’s BAC by between 0.02% and 0.025%.  One standard drink is considered to be one 12 fluid ounce (355 ml) of 5% alcohol by volume (ABV) beer, or one 5 fluid ounce (148 ml) of 12% ABV wine, or one 1.5 fluid ounce (44 ml) of 40% ABV (80 proof) shot of hard liquor.  So, two standard drinks will raise your blood alcohol concentration to about 0.05%, three standard drinks will raise your BAC to about 0.08%, and four standard drinks will equal 0.10% BAC, without taking size differences into consideration.  The general rule of thumb is, for an average sized American woman it takes drinking three standard drinks in an hour, and for an average sized American man it takes drinking four standard drinks in an hour to reach a BAC of 0.08%. 

Editorial Staff, “How Many Drinks Does it Take to Reach a .08 BAC?”
Patrick T. Barone, “How Many Drinks Does it Take to Get to a .05 Legal Limit?”,



Sources


Barone, Patrick T.; “How Many Drinks Does it Take to Get to a .05 Legal Limit?”, May 8, 2018 [BaroneDefenseFirm.com, 2020], https://baronedefensefirm.com/blog/how-many-drinks-does-it-take-to-get-to-a-05-legal-limit/, accessed February 29, 2020

Department of the Air Force, Survival Training Edition, AF Manual 64-3, [US Government Printing Office, Washington DC August 15, 1969] p 1.13 - 1.15

Editorial Staff, “How Many Drinks Does it Take to Reach a .08 BAC?”, June 13, 2014, [Ignition Interlock Help, 2018] https://www.ignitioninterlockhelp.com/blog/many-drinks-take-reach-08-bac/, February 29, 2020

Gillin, J. Christian; “How Long Can Humans Stay Awake?”, March 25, 2002, [Scientific American, A Division Of Springer Nature America, Inc., 2020], https://www.scientificamerican.com/article/how-long-can-humans-stay/, accessed March 26, 2020

Grossman, Dave, Lt. Col., and Christensen, Loren W., On Combat, 4th Edition, [KRG, LLC, 2008], p. 24

Rodulfo, Kristina; “Sleep Deprivation Is The Same As Being Drunk, Study Says”, Elle Magazine, April 5, 2016, [Hearst Magazine Media, Inc., 2020], https://www.elle.com/beauty/health-fitness/news/a35349/lack-of-sleep-same-as-being-drunk-uk-sleep-study/, accessed March 24, 2020

Townsend, Stephen J., Major; The Factors Of Soldier's Load, [Fort Leavenworth, Kansas, 1994], p. 56, http://www.themilsimperspective.com/wp-content/uploads/2018/10/a284389-THE-FACTORS-OF-SOLDIERS-LOAD.pdf, accessed 02/02/2020

Vandergriendt, Carly; “How Long Can You Go Without Sleep?”, March 16, 2018 https://www.healthline.com/health/healthy-sleep/how-long-can-you-go-without-sleep#what-happens-after-24-hours, accessed March 26, 2020


Sunday, March 22, 2020

So, What’s in Your Possible Kit!? ©

 
The author’s possible kit, photograph by the author.

This is the fourth installment of the Oelslager Files, articles inspired by the works of the late Dr. Robert William “Doc” Oelslager.  Also, since everyone around the world is dealing with COVID-19, I thought something lighter and non-virus would be a good thing. – Author’s note

So, what’s in your “possible kit”!? 

Have you even ever heard of a possible kit?  It’s possible you might be asking yourself right now, “what’s a possible kit?  And maybe you are thinking, “isn’t that just another name for a survival kit?

In my mind a possible kit isn’t a survival kit, it is more like a toolbox, or maybe, depending on your level of organization, a junk-drawer, full of a little bit of everything.
Personally, whenever I head out into the wilderness, I always bring my possible kit, my personal first aid kit and my survival kit.  I always have both my personal first aid kit and my survival kit on me, and I keep my possible kit in my pack.  A possible kit should complement your survival kit and it should be available for everyday use, while a survival kit is for emergencies only1.  Think of it as a kit for “it’s possible it might happen” or “it’s possible I might need it

“So, What’s In Your Possible Kit!?”

My possible kit only weighs 8 ounces (227 grams) and here is what I keep in it.

 
The author’s possible kit, enumerated, photograph by the author.

1)     A zippered pouch to hold all the “possibles”.
2)     A LED flashlight, a spare in addition to the one in my survival kit and first aid kit.
3)     3 spare AAA batteries for my headlamp and the flashlights in my first aid kit, survival kit and possible kit.
4)     A Swiss+Tech®, multi-tool, with needle nose pliers, a saw, a Philips head screwdriver, can opener and knife.
5)     A flat head and a Philips head screwdriver for repairing eyeglasses.
6)     An eye glass repair kit: screws, spacers, nose pads and a cleaning cloth
7)     16 feet (almost 5 meters) of 15-pound test, braided nylon line, for use as heavy sewing thread.
8)     2 feet (.6 meters) of 22 gauge (.73 mm) galvanized steel wire.  I have used wire like this in the past to reattach the sole of a water shoe to its upper.  Wire can be used for repairing just about anything.
9)     2 large eyed, heavy duty sewing needles: the smaller one is a # 17 carpet needle that is 2 inches (52 mm) long and the other one is a #14 darning needle that is 3 inches long (78 mm).  Both are stuck into a piece of heavy-duty nylon patch cloth.  The large elongated eyes on the needles make threading them, much simpler.
10)   4 large safety pins stuck into another piece of heavy-duty nylon patch cloth.
11)   A pencil.
12)   A pencil sharpener.  This is also very useful for making fine tinder to help you get your fire started.
13)   A file to sharpen my axe with, an axe without something to sharpen it, is just an oddly shaped hammer
14)   A whetstone to sharpen my knives.
15)   A 5 foot (1.5 meter) long tape measure.  I have used this to measure and diagram an old logging blaze on a stump on the shore of Lake Louisa, Algonquin Provincial Park (for pictures of the stump and my drawing, see “The Madawaska River Loop: Whitefish, to Pen, to Harry and Louisa…And Back Again! Part One ©”, HERE)
16)   A thermometer, emergency whistle, magnifying-glass, pocket compass, all in one all-purpose tool.
17)   5 mini-zip ties.  When I reattached the sole of the water shoe to its upper, I also used some small zip ties to complete the repair.
18)   3 heavy-duty rubber bands.  These originally came wrapped around celery stalks from the grocery store, they have literally 1,001 uses.

 
An excerpt from the 1969 edition of Survival Training Edition, AF Manual 64-3, page 1-4.  Notice how many of the items in this list are in my possible kit, which is why I say that possible kits can and should complement your survival kit2.

Now the nice thing about possible kits, is that you can put anything into them, whatever you think you might need at some point in your travels. 

 
An excerpt from Scouting magazine, March/April 1982, page Scout 3 Jul 82, also reproduced in R.W. Oelslager’s The Winter Experience, figure 639, page 325

The possible kit shown in Scouting Magazine, March/April 1982, which was also reproduced in R.W. Oelslager’s The Winter Experience, included aspirins and band-aids, which are things that I keep in my personal first aid kit.  Since, I always keep my personal first aid kit in my pocket when I am in the wilderness, I don’t include first aid supplies in my possible kit.  Additionally, this kit included matches, a razor blade, fishhooks and tape, which are things that I keep in my survival kit.  It also included a dime, which for all of you who were born into the age of cell phones, was needed to make an emergency phone call home from a pay phone.

 
An excerpt from a Ziploc® advertisement, found in Field & Stream, May 1988, page 124

And you don’t have to be to fancy with the pouch for the possible kit either, many people simply keep their possible kit in a Ziploc® bag. 

So, what’s in your possible kit!?

I hope that you continue to enjoy The Woodsman’s Journal Online and look for me on YouTube at Bandanaman Productions for other related videos, HERE.  Don’t forget to follow me on both The Woodsman’s Journal Online, HERE, and subscribe to BandanaMan Productions on YouTube.  If you have questions, as always, feel free to leave a comment on either site.  I announce new articles on Facebook at Eric Reynolds, on Instagram at bandanamanaproductions, and on VK at Eric Reynolds, so watch for me.

That is all for now, and as always, until next time, Happy Trails!


Notes

1 In case of emergency, there is a good chance that I will end up separated from my luggage and my possible kit.  And even though there might be some duplicated items between my possible kit and my survival kit, as long as I can carry the extra weight, I’m OK with the overlap.



Sources

Department Of The Air Force, Survival Training Edition, AF Manual 64-3, [Air Training Command, U.S. Government Printing Office, Washington, D.C., August 15, 1969], p. 1-4


Ziploc® advertisement, Field & Stream, May 1988, Vol. XCIII, No. 1, [Times Mirror Magazines, New York, NY] p. 124


Sunday, March 15, 2020

COVID-19, And A Simple, Homemade Respiratory Mask ©


 
An excerpt from “Simple Respiratory Mask”, page 1033
For a video demonstrating how to put on the mask built according to the study a "Simple Respiratory Mask", go HERE or HERE, -- Author's Note  

With the current concerns over the COVID-19 and shortages of masks, and with the sincere hope that you never need this information, I am writing this article.  I am not an alarmist, I haven’t bugged-out for the woods...yet, laugh out loud!  I like to read about prepping though, my Father says that I would stop to read soup labels and he’s probably right.  I am also not a doctor and I don’t even play one on TV.  I just read a lot and I found this article several years ago and thought that I would pass it on to you. 

I am not saying that you need to stockpile N95 masks or make homemade, simple respirator masks because of the coronavirus, however “forewarned is forearmed1 and it never hurts to know how to do things.  A simple homemade respiratory mask, equivalent to a N95 mask, made with locally available materials, which can be washed and sterilized with methods available worldwide, “...may be a solution if commercial masks are not available2. 

However, before I begin I need to share the opinions and disclaimers of the CDC with regards to this article, since it was published on their web site: “The conclusions, findings, and opinions expressed by authors contributing to this journal do not necessarily reflect the official position of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above3.  So, draw your own conclusions from the material below, I am not offering medical advice and I do not represent, endorse, guaranty or warranty this information: it is simply provided for your continuing education and enlightenment.

 
Photograph by the author.

There are two types of face masks, and the air purifying respirator masks like the N95 masks offer more protection than a simple disposable medical face mask or a surgical mask, both of which are generally loose fitting.

Disposable face masks simply create a barrier between your nose and mouth and splashes or large particles and droplets.  They cannot filter out the very small particles or droplets that are created when people talk, sneeze or cough.  They also do not fit tightly around your face and therefore, they allow air to leak under the mask and into your mouth and nose.  This type of mask, by definition, is disposable and if they become damaged, dirty, soiled or stained they should be disposed of and replaced with a new mask.

The U.S. Department of Labor recommends air purifying respiratory masks, either N95, N99 or N100 masks for workers working with victims of viruses.  Remember viruses like the corona virus, COVID-19, spread when infected people sneeze, cough or talk, spewing droplets containing the virus into the air and possibly into the eyes, mouth, nose, throat or lungs of a nearby person.  The greater the N-value of a mask, the greater the protection a properly fitted mask provides: N95 respiratory masks are 95% efficient at filtering the 0.3µ (micron) particles created when people talk, sneeze or cough.  Another thing to know about N95 masks is that they can be fatiguing to wear, the authors of a “Simple Respiratory Mask”, noted that while the testers wore this mask for an hour without any difficulty, they could not comment on what it was like to wear while performing strenuous work or in adverse environments.

 
Photograph by the author.

To make this simple respiratory mask you will need a heavy-weight T-shirt.  The authors of this study used a Hanes Heavyweight 100% cotton T-shirt made in Honduras, I used a Gildan Ultra Cotton, 100% pre-shrunk T-shirt, made in Nicaragua.  You will also need a pair of sharp scissors and a ruler or tape-measure, and a magic marker doesn’t hurt. 

Before beginning, boil the T-shirt for ten minutes and then air dried it, this maximizes shrinkage and sterilizes the cloth: this method of sterilization is available worldwide.
 
An excerpt from “Simple Respiratory Mask”, page 1033
   
Step One: The Outer Layer

To make the outer layer, you need a piece of T-shirt that is 14-½ inches tall to just over 28 inches long (37 cm tall by 72 cm long).  I found that if I cut upwards to the bottom of the sleeve and then around the back of the T-shirt to the bottom of the other sleeve and then another 5 inches (about 13 cm) further around towards the front of the shirt, I would end up with a piece of cloth with the correct dimensions.






 
Photographs by the author.
  
Step Two: The Inner Layers

In this step you will make the eight inner layers for the simple respiratory mask from pieces of T-shirt that are 7 inches tall by 7 inches long (18 cm tall by 18 cm long).  I found that I was able to cut out three of the inner layers from the material on the back of the shirt between the sleeves.  The other five pieces came from the front of the shirt. 

If you have a wide face, the authors of this study, suggested that you make and use inner layers that are larger than 7 inches square (18 cm by 18 cm square), so that you will have less air leakage when you wear the mask.




 
Photographs by the author.
  
Step Three: Making the Ties

This step is the easiest.  First, I assembled the inner layers; two layers cross-grain, two layers straight, or lengthwise-grain, two layers cross-grain, and finally two more layers laid straight-grain.4  I placed the assembled inner layers onto the bottom center of the outer layer.


 
Photographs by the author.

  
Next, I measured down 5-½ inches (14 cm) from the top edge of the outer layer and then made a 9 inch (23 cm) long cut in towards the center of the outer layer, I did this on both sides  This creates tie “A” which is then rolled down, in a roll that is about 1-¼ to 1-½ inches wide (32 to 38 mm), stopping at the top edge of the inner layers.  Measure up from the bottom edge of the outer layer by 6 inches (15 cm) and then cut in toward the center on both sides, making a cut 9 inches (23 cm) long; and these two cuts create ties “B” and “C”
 
Photograph by the author.
  
Step Four: Making the Nose Slit
 
An excerpt from “Simple Respiratory Mask”, page 1033






 
Photographs by the author.
  
Make a “nose slit” for the bridge of your nose in the center of tie “A”.  Measure in from either edge about 14 inches (36 cm) and make a slit about a ¼ inch (64 mm) from the top and bottom edge of the 1-¼ to 1-½ inches wide roll that is tie “A”.  This slit should be 1 inch long (25mm) and penetrate through no more than three layers of tie “A”.
 
An excerpt from “Simple Respiratory Mask”, page 1033
  
Now that the mask is made it is time to put it on.  I found that it is easier to put the mask on in front of a mirror.  Start by putting the “nose slit” in tie “A” over the bridge of your nose and then tie, tie “A” below the back of your neck.  Adjust the fit around your nose and cheekbones to eliminate any air leakage.  If the seal is not tight and there is air leakage, the authors of a “Simple Respiratory Mask” suggest that you push the rolled fabric of tie “A”, up or down on your cheekbones until the leakage stops.  If the seal is still not tight the authors further suggest that you push extra T-shirt material under tie “A”, between your cheekbones and your nose.  I cut out an extra 7 inch by 7 inch (18 cm by 18 cm) piece of T-shirt to use as an air leakage cloth.
 
Photograph by the author.
  
Next tie, tie “B” over and on top of your head.  If the ties are too short, knot extensions to each end of tie “B”.  I cut out extensions which were 3 inches wide by 9 inches long (8 cm wide by 23 cm long) from the remains of my T-shirt.  These are about the same dimensions as tie “B” and should give you plenty of length to knot this tie over your head.

And the last step in putting on this mask, is to tie, tie “C” behind your head and voila, you are masked.
 
Note the roll of cloth, just visible on the bridge of my nose, tucked under my mask to stop air leakage
 
Photographs by the author.
  
The authors of a “Simple Respiratory Mask” noted that commercially available N95 respirators required a fit factor of 100 against aerosol contaminants to be considered adequate in the workplace.  The homemade mask featured in the “Simple Respiratory Mask” study, achieved with one author, a fit factor of 67 and a fit factor of 13 and 17, with the other two authors, who had larger faces.  The authors felt that this homemade N95 respiratory mask would have a lower fit factor and therefore be less effective than commercially manufactured N95 respiratory masks.  They felt that this would be especially true when these homemade masks were made by amateurs.  Additionally, they thought there might be problems due to variations in locally available materials, cultural practices, facial structures, beards, etc.  It should be noted that when using any respirator, you need to be clean-shaven...sorry guys!  The authors of this study did not recommend using this homemade mask in place of a commercially manufactured N95 mask, however they did feel that this homemade mask provided a good fit and a measurable level of protection from aerosol contaminants.  In the end it comes down to “something is better than nothing”.

I hope that you continue to enjoy The Woodsman’s Journal Online and look for me on YouTube at Bandanaman Productions for other related videos, HERE.  Don’t forget to follow me on both The Woodsman’s Journal Online, HERE, and subscribe to BandanaMan Productions on YouTube.  If you have questions, as always, feel free to leave a comment on either site.  I announce new articles on Facebook at Eric Reynolds, on Instagram at bandanamanaproductions, and on VK at Eric Reynolds, so watch for me.

That is all for now, and as always, until next time, Happy Trails!


Notes

1Forewarned is forearmed” means that you can be appropriately prepared if you know something in advance.  Knowledge in advance enables one to be prepared in advance. This expression originated as a Latin proverb, Praemonitus, praemunitus, which was translated into English by the early 1500s as “forewarned, forearmed”, and it has a similar meaning to the saying “a word to the wise”.  From the Free Dictionary by Farlex, https://idioms.thefreedictionary.com/forewarned+is+forearmed and The Phrase Finder , https://www.phrases.org.uk/meanings/forewarned-is-forearmed.html

2 Virginia M. Dato, David Hostler and Michael E. Hahn, “Simple Respiratory Mask”, page 1033

3 CDC, Center for Disease Control and Prevention, Emerging Infectious Diseases

4 According to the web site, The Spruce Crafts, “What Is a Fabric's Crosswise Grain?”, cross grain is “The crosswise grain of a piece of fabric is a term that describes the threads that run perpendicular to the length of fabric as it comes off the bolt”, this grain runs across the width of the cloth.  Therefore, straight or lengthwise grain of a fabric is the term that describes the threads that run parallel to the length of the fabric as it comes off the bolt.


Sources

CDC, Center for Disease Control and Prevention, Emerging Infectious Diseases, June 2006, Volume 12, Number 6, https://wwwnc.cdc.gov/eid/article/12/6/05-1468-f1, accessed March 5, 2020

Dato, Virginia M., Hostler, David, and Hahn, Michael E. “Simple Respiratory Mask”, Emerging Infectious Diseases, June 2006, Volume 12, Number 6, p. 1033-1034. https://dx.doi.org/10.3201/eid1206.051468, accessed March 5, 2020

Kekatos, Mary; “Mask mania”, February 27, 2020, Dailymail.com, https://www.dailymail.co.uk/health/article-8051799/Can-face-mask-really-protect-against-coronavirus.html, accessed March 5, 2020

Wickell, Janet; The Spruce Crafts, “What Is a Fabric's Crosswise Grain?”, https://www.thesprucecrafts.com/what-is-a-fabrics-crosswise-grain-2821571, accessed March 10, 2020