Synthetics: Just HOW warm when wet?

This will be my third season kayaking. Last year I took a couple trips in the 3-4 day category. I packed several changes of clothing, which is fortunate since it rained one entire day! And, I went through most of my dry clothing. I shudder to think what would have happened if everything became wet on day one!

Up to now, other than a rainsuit, I made due with regular clothing: sweatshirts, pants, etc.

This Christmas I got a set of poly underclothing. Other than that, I don’t own any synthetics.

So here is my question. Synthetics are supposed to be much warmer than cotton when wet, but just HOW warm? If caught in rain or otherwise damp, on a multi-day trip, would I still be comfortably warm, or is it just a RELATIVE thing (wet and cold, but not AS cold?). Would I still need several changes of clothing, or could I cut back? What has been your experience on multi-day trips.

not an expert, but…
you still need to layer, etc. also, conditions are a big factor. having said that, synthetics are A LOT better than cotton. sometimes while paddling in winter conditions in Southwest Florida I forget I’m wet until I get out of the boat. you just don’t notice, unless it’s cold as hell. nowadays you can get synthetic shirts, fleece jackets, etc. at pretty good prices at many clothing stores. for rain, a rain jacket or parka with layers underneath will work. i only carry one full set of clothes when on a trip. that set may consist of 10 pieces, though.

No, not the diapers.

How warm depends on how thick (loft when wet), how close-fitting (closer is warmer), and probably on the structure of the individual fibers themselves.

Any of them them will be warmer than your wet cotton sweatshirts.

Another factor is how fast do they dry after getting wet? That’s one of the reasons cotton is so poorly suited to paddling; it takes a long time to dry for a given thickness.

You should always have at least one change of dry clothes available. If you wash and dry your clothes every day (don’t laugh–I’ve done this in sunny climates/regions), then you only need 2 sets. If that’s not guaranteed, you should carry a 3rd set. Fortunately, many synthetics compress better than cotton. The exception is thick fleece or pile.

I too am not an expert but can tell of one experience.

One March day I was paddling in New Jersey and flipped over. The air was about 50 degrees with a light wind. I was wearing a polarfleece ( synthetic) jacket. Fortunately I was paddling in a tidal creek(only 50 yards wide) and could swim and walk quickly to the bank, empty the kayak and reenter. It wasn’t until the next day that I realized I had not felt the cold. Adrenaline? Certainly not when paddling a half mile back to the put in. I credit the polar fleece for keeping me warm in spite of being soaked.

polys will keep
ya warmer than cotton. wet or dry. Dry they wick sweat away from your body. You still need a change of clothes if you get wet.

Cotton vs…almost anything else
I can’t honestly say I’ve spent multiple days without access to dry clothes, so I’ll leave that to those with more experience. However, my 30 years ice-fishing and 20 years deer hunting ought to be a start–plus doing a lot of other stupid things in cold, wet weather.

Cotton, in cold, wet atmospheres, stinks. There is a saying, “cotton kills.” I absolutely refuse to wear cotton if I am going to be active, far from home, and the temperature gets below 40-50 degrees. Wet and cold is a recipe for hypothermia, and I’m not going there if I can avoid it.

That said, being wet (as in immersed, and/or “rained on”) is almost always no fun, regardless of the fabric you are wearing. If you have the possibility of getting wet, you should try avoid it. Rain gear, proper shelter, and proper boating techniques can help keep you from getting sopping wet (or as wet). I don’t have the statistics, but being wet increases heat loss dramatically over being dry. Many fibers help wick moisture (takes it away from the skin, thus making you “drier”) and insulate (hold warm air next to the skin) better than cotton. How much better? Again, this is probably measured somewhere by a scientist, but people’s tolerance of cold and wet varies from person to person.

Assuming you are a canoeist or a kayaker, both activities make a person sweat over time, and synthetics (or wool, still my favorite) do a better job of keeping you from being miserable. Plus, synthetics may allow you to change clothes less often, giving you a chance to wear the warm, clean dry set on your way out, rather than a sodden lump of cotton, or your last wet set of polypropylene.

Case in point: If I walk a long distance onto a frozen lake in cotton long underwear and I perspire to some degree, I can usually count on feeling cold within 30 minutes to an hour of when I stop moving, especially if there is any kind of wind. If I do the same in polypropylene, I might feel a little cooler, but I don’t have the ice-water chills and rapid hypothermia symptoms as quickly. Yes, you can defeat cold by wearing other layers and a wind-blocking layer, but if you were smart enough to wear these layers, you’re smart enough to leave the cotton home.

Wet and cold is still wet and cold. I would suggest that bringing the same amount of gear (and no cotton) in wet, cold environments will increase your chances of having garments that will keep you comfortable, rather than miserable.

My last, insignificant point is a mental shield: I know how miserable I used to be while hunting/fishing in the cold in cotton long underwear. Just knowing how much less miserable I am while wearing something else is comforting mentally, and a positive mental outlook is invaluable.

wet is wet
I once had a guy show up for a weekend trip down a local river. The weather did not help the start of our trip and by the time we were loading the boats by the shore it had started to rain. My pal arrived a little late and when he got out of his truck he was grinning from ear to ear; seems that he had just come from the local outdoor shop and had purchased one of those new synthetic wikaway shirts. He was absolutely sure that this shirt was going to keep him dry because that is what the advertisement said. We just smiled and complimented him on his new shirt. Needless to say, the rain that ensued over the next three hours got him just as wet as all the rest of us. And nobody is comfortable when their clothing is wet. That being said, synthetics will dry faster if they get wet, thus you are wet for a shorter period of time. And, as they start to dry, they will start next to the skin so you will feel drier sooner. I wear nothing but poly and nylon. It works better, is lighter, packs smaller, and dries faster.

Depends on the synthetic. Nylon soaks
up water to a certain degree, unless the fibers are surface-treated. Nylon relaxes a bit when wet, so a nylon garment may feel wet, heavy, and saggy. Dacron/polyester has much less water affinity, and the fibers are much less inclined to stretch when wet. That’s why sails are often made of Dacron. Dacron/polyester also resists sun better than Nylon. Polypropelene does not soak up water and has very little surface affinity for water, so polypropelene underwear will tend to feel dry.

So-called wicking fabrics are made of fibers which do not soak up water, and they have a surface treatment which DOES have an affinity for water. When worn next to the body, a wicking fabric will take up moisture from the skin surface, and then the temperature gradient will move the moisture along the wicking fibers until (one hopes) it evaporates somewhere. Note that, under a Goretex drytop, the moisture is only going to go through into the outside environment if there is both a temperature and a moisture gradient. In other words, if it is raining, moisture is not going to move outward much at all.

Note that with a wicking poly garment, the fibers MUST have surface affinity for water to wick properly. If you are wearing, say, an expedition weight wicking poly garment, and nothing else, and you take a swim, the wicking surface treatment is going to hold a significant amount of water in the weave of the garment. If you were wearing a non-wicking polypropelene garment, or perhaps a polyester garment with a water-shedding treatment, much of the water would quickly run out of the garment, restoring the air spaces more effectively for warmth.

The conclusion: wicking poly garments are for wearing next to your skin, under other layers which provide additional loft for warmth. A wicking poly garment is NOT a garment for taking a quick swim and dripping dry fast. Wicking garments do NOT drip dry as quickly as polypropelene or non-wicking polyester.

and cotton is the ultimate, wicking, water absorbing material. Cotton will absorb water into the fiber, eliminating any trapped air, making it useless as an insulator.

You can wring the water out of synthetics, such as; polypro, polyester, fleece. The synthetics will retain their structure and trap body heat. If you wring water out of cotton, it will retain much of the water and the fiber structure will collapse, preventing any air retention, and thus, insulating ability.

Wool for warmth used to be the standard.
I read that dry wool actually releases some heat when first doused. Of course, your body heat has to supply the energy to dry the wool garment out again. Best thing about wool is that it absorbs rather little water, keeps its loft, and will drip out to some extent. Also, the fibers are springy and this helps retain loft.

I too am a big fan of wool. I recently started to wear a wool jersey and long john under my drytop/drypants for cold water paddling.

I used to wear mostly synthetics (polypro, fleece).

I find wool to be more comfortable when it’s wet than synthetics- which I thought tended to feel clammy under a drytop/pant.

Wool also seems to be more comfortable over a wider temperature range.

Only drawback is that good wool garments are a lot pricier than the synthetics.

Warmth, drying, wool
There are basically two qualities to synthetics, and a given material will usually be better at one than the other. Some synthetics are designed to dry very quickly, some are designed to retain body warmth when they are wet. You’ll need some of each over the course of a few days camping, with the proportion depending on the kind of weather you expect and how fussy you are about smelling like a melange of campfire smoke, bug spray and yourself. Think in layers. Both types compress quite well.

Wool is actually one of the oldest of materials on the water because it retains its warmth when wet. I can attest to this - a horrid old, very soaked wool sleeping bag was the diff between advancing into serious hypothermia and not once in my younger (and stupider) days. The problem with wool is that it’s heavy when wet and doesn’t dry out fast at all. But you’ll find newer materials that have some amount of wool blended in with synthetics to take advantage of the best of boat. Often pricier, but very comfortable.

I switched to a silk base layer two years ago. Socks, longjohns and tops. I have never been more comfortable. Light wool or synthetic 2nd layer, and a windproof/waterproof top layer. It is real important for this top layer to have very good ventilation (arm pit zips, back flaps, etc.) Good to about 40 degrees, and then another layer of either heavier wool or pile under the windproof if it is colder. Use it for spring canoeing, and xc and downhill skiing.

The biggest advantage of silk–when I am in my sleeping bag with nothing else on–damn it feels sexy.

Seriously, the main ingredients to comfort are(regardless of what you wear) 1) don’t overheat, 2) stay dry, 3)stay clean, and 4) dress in layers. And if you are lonely, wear silk.

I am “rediscovering” wool
I love wool more and more all the time. Wool outer garments are awfully bulky if packing space is a concern, so I don’t use wool jackets that much, but for middle layers (basic shirt and pants), it works great. I can attest that it loses very little of its insulating ability when wet. The new merino wool is supposed to be really nice for longjohns too (merino is non-scratchy), but I haven’t tried it yet.

what about acryl?
is acryl good for underwear? Facts, experiences?

Acryl is warm and feels soft, dries faster than wool.

I know (only) one kind of underwear made from acryl,

and it is a lot cheaper than wool or polyester.

But I wonder how it would perform compared to

polyester or polypropylene underwear.

Might want to know how insulation works!
Ya might want to know the principle so you can judge for yourself. Nothing is warm by itelf, the principle is how does it trap air, which CONDUCTS heat away from you 25 times slower than when wet. Any material that is soaked will conduct heat away at the same rate. Cotton is no worse, just takes longer to dry out and little or no air insulating you when it gets wet. Wool can retain some air, hence slower conduction, but it can become soaked too, so no magic.

Remember CONDUCTION is a big cold challenge but so are Evaporation, radiation, and convection. A shell is important to slow both evaporation and convection, so even in cotton one loses heat slower.

Don’t be fooled that synthetics will keep your heat, at most they may dry faster.

I find that the best combination is the best gore-tex and or eVent jacket shell AND a thin vest of Primaloft or Polarguard Delta. These two insulators retain from 75% to 100% of insulation when soaked and then drained.

I use
polypro underwear and wool outer garments as a back up dry set incase I get wet. Mil. surplus wool clothes are cheap and work well.

Cotton holds more water than wool or synthetics. Water absorbs heat. Wet cotton is colder than wet wool because of that.

The only cotton I carry are my bandanas and a T-shirt for sleeping. The T-shirt prevents that clammy feeling you can get from a sleeping bag. It also keeps your sleeping bag drier. That’s a huge plus when camping in sub-zero conditions.

I carry tights instead of pants. A pair of shorts worn over the tights provides pockets and butt protection. It may look weird but the tights are warmer than Levis and far more comfortable.

Cotton T’s
When I run in cool to cold temperatures, I stay with the cotton T or doubled under a long sleeve cotton T. The time I ran in a super wicking fabric I about froze- the more I ran, the more the evaporation and never did warm up. Just another viewpoint. And, worse case, just stop at my front door and go inside.

Cotton Kills
I lived for 7-8 years in South Florida and never wore anything but cotton because it was cool and felt good.

When I moved to the Sierras it took me a while to ditch the thick cotton sweatshirts, but I learned the hard way.

Mysterioso is really good, but not something you want to wear for several days. It starts to smell…