how to handle base layers in freezing rain

Youll be fine with your two sets of baselayers

Just make sure you are using synth …

And bring a container that can hold hot water, like a nalgene

At 40F you migh need more than a mid weight fleece though

;)

I find fleece, especially the lighter weight baselayers, to dry rather quickly under normal body heat so long as you're out of the rain. If you stay warm an hour before turning in you may find your baselayers already dry. Of course this temp range is perfect for hypothermia so your mileage may vary.

All rain jackets eventually fail in a continuous downpour. You can prevent that by keeping the rain off the jacket with a hiking umbrella. Morally it's also a lot nicer since you're basically hiking under shelter.

Francis Tapon summed it up well: http://francistapon.com/Travels/Advice/10-Reasons-to-Go-Hiking-and-Backpacking-with-an-Umbrella

How interesting! Tangentially, I noted that Francis doesn't use trekking poles. I was relieved to see that since they are awe-inspiringly expensive.

David-

Plenty of influential ultralight names don't use poles (Mike Clelland, Ray Jardine). Personally I like them. If budget is the issue, check out the Costco pair.

I'm holding out on trying an umbrella until someone designs a pole extender that could turn an umbrella into a trekking pole when not in use.

Your system should work. Here's what I use:

A light weight base layer and either a 100 or 200 weight fleece during the day. 100 if lots of effort or mid day. 200 (or a second 100) if it's raining and 30-40 degrees. I tried a 200 weight vest over the 100 wt fleece, but it wasn't enough.

In camp and at night, I want a mid weight puffy instead of a 200 wt fleece. It's much warmer – and a sweater weight puffy wasn't enough. I go with synthetic if I expect rain more than 6 hours per day AND it's a high humidity area (east coast etc).

For sleeping, I use one of the fleec jackets over my legs, and the puffy jacket over my torso if the weather is unexpectedly cold, or I'm so tired I'm not generating as much heat as usual.

> I've been told that clothing should be kept comparatively light during the day due
> to body heat generated from hiking, but at night, warm, dry clothes are needed.
Yes, yes, yes.

Cheers

Most people wear entirely too many cloths while hiking. You don't need a rain shell just because it is raining. I routinely hike in shorts and a t-shirt in cold rainy weather. While you are exerting yourself you have nearly zero chance of becoming hypothermic. If it is blowing hard and you get cold while under exertion you don't need extra insulating layers until you first put on a shell and STILL find your self dangerously cold.

Keep your insulating layers in your pack and dry until you need them in camp. If you are moving and exerting yourself you can always error on the side of keeping cold rather than pulling out layers that could stay otherwise dry for camp. In camp you will be glad that you have dry usable clothing.

Start the day cold… or peel layers quickly after warming and put them in your pack. At the end of the day get shelter up before pulling out your insulating layers. Focus on keeping layers dry and learn to dry them with body heat at night. Moisture management is easily learned but you have to think about what you are doing and continuously manage moisture by learning to keep things dry and drying those that get wet.

While you are exerting yourself you have nearly zero chance of becoming hypothermic.

"After both Honolulu and Trim hiked out, I quickly decided that hanging out in my tent all day around a lonely lake with bad weather didn’t seem that appealing. The rain had momentarily softened from full gale to downpour, which gave me the best opportunity I’d seen all morning to break camp. I grudgingly unzipped my sleeping bag and packed up everything inside my tent. I put on a pair of non-waterproof wind pants over my hiking shorts because that’s all I had and it looked way too nasty to be walking around in running shorts. All I had on the top half of my body was a long sleeved shirt and a thrashed rain jacket. I put on my flimsy liner gloves, hustled out of my tent and packed the soaking wet jumble of nylon into the big mesh pocket on the outside of my pack.

I hiked out in the downpour. My wind pants were soaked within ten minutes. They clung to my damp skin like a sandwich wrapper to a soggy BLT. I had to wipe my sunglasses every three minutes just to see where I was going. It was ludicrous I even had them on in the first place, but I had surmised they would deflect some of the blowing rain. My liner gloves absorbed water like a dish sponge. I stuck my soaking wet hands into the soaking wet pockets of my soaking wet pants and started to shiver a bit as I hiked on. I had only been on the trail for thirty minutes. This was not good.

…..

I started to shiver and decided that I needed more clothes on my upper body ASAP. I could have gone for an Eskimo’s parka with hood and waterproof shell but my thinly insulated jacket would have to work. I dug down in my pack as water poured off the bill of my hat. I grabbed the insulated jacket and put it on as swiftly as possible and slapped my rain jacket back on over it without delay. I reached down to zip up my insulated jacket and simply couldn’t. My fingers wouldn’t work. My brain was telling my hands to zip my jacket, but they simply could not grasp the zipper. I had lost all dexterity in my fingers. I couldn’t zip my jacket and I was in a pouring cold rain. My hiking partners were up ahead so they had no clue as to what was happening to me. I was utterly alone in a torrential downpour and I couldn’t zip my stupid jacket. A bolt of panic ran up from my stomach to my throat and for about 10 long seconds I thought about dying."

http://www.backpackinglight.com/cgi-bin/backpackinglight/ihike_hypothermia.html

There is always going to be an exception. But in thousands of trail miles I've been in a situation where I've needed to worry about hypothermia while moving exactly zero times.

In the military… another story. I was forced into a combination of exhaustion, little food, little rest and having everything I owned wet for extended periods at temps in the 30s & 40s. Even then it was when we stopped moving where hypothermia was the biggest threat. When backpacking you typically have much more control over your situation. You can moderate your exertion to prevent exhaustion, you have more freedom over how to wear and store clothing (and which clothing to carry). You eat when needed and overall you can seek shelter of some sort if things are sketchy.

So… I'll stand by my statement. It is extremely rare to face hypothermia while moving and backpacking and you shouldn't choose layering approaches based upon the assumption that hypothermia is likely if you don't insulate while hiking. Your much better off running on the cold side while moving and keeping your insulation dry for times of inactivity when hypothermia is the biggest threat.

The author of the above link is a normal backpacker in normal "caught unprepared" in the rain circumstances

While you can generate body heat while moving … This may not be enough if its very windy while raining or when moving slowly because of technical ground or darkness

Also remeber that many BPLers may be a bit elderly or women who generally generate less body heat than healthy young males

I definately agree with keeping your "static" insulation dry

However ive had folks get mildly hypothermic even when active in poor conditions, especially if they are forced to move slowly by terrain or circumstances

A rain jacket will keep you damp and warm, rather than wet an cold especially in good winds

You cant simply power up the body heat by being more "active" in every situation to offset winds and a 40F rainstorm

Remember … You can be wet OR cold and you mught survive … If yr both yr dead

"While you are exerting yourself you have nearly zero chance of becoming hypothermic."

You must run a lot warmer than me. This July in Yosemite I had to bail and run below the treeline because I was wearing shorts + base layer + rain jacket with no mid layer and I couldn't keep warm enough walking on flat ground.

In mid 30's or around freezing with rain I can't walk downhill without a mid layer without shivering which would lead to hypothermia.

Recently another poster mentioned, I think it was on the JMT, where he got dangerously cold in a storm and had to set up shelter asap to avoid hypothermia.

Also I don't enjoy hiking 12 hours straight to keep warm without stopping to take a break.

To answer the OP, a light fleece vest is nice for quick on/off.

Hypothermia is real, that's for sure.
The harsh reality is that Nature does not care. If you make the wrong decisions, you may die. If you take the wrong gear to the mountains, you may be making the wrong decisions.

Cheers

"While you are exerting yourself you have nearly zero chance of becoming hypothermic."

I rarely call out misinformation that I see posted on forums in general but this is so completely and utterly wrong, to say nothing of dangerous advice! Most people who become hypothermic do so while exerting themselves!

When I took my initial first aid course over 35 years ago, they showed us a short movie, "By Natures Rules" I think. It was a drama of a backpacking group heading out in nice weather, and then the bad weather sets in halfway up the mountain. The leader had to be treated for hypothermia.

–B.G.–

James

> Most people who become hypothermic do so while exerting themselves!
Can you provide any published statistics to support this rather strange claim?
Unless 'exerting themselves' simply means 'being outside doing something'? In which case it is a meaningless statement. (It is not often one becomes hypothermic while inside.)

Cheers

Roger, I think what he is saying is that when actively moving you are to keep warm enough that hypothermia is not possible with a rain jacket and base layer.

That is overly general and only makes sense for 3 season conditions.

Serious storms happen in midsummer at high elevations.

I was in exactly this situation this August 3 in the sierras. I was hiking out from the JMT over Bishop pass in a rainstorm that got progressively colder and windier as I got closer to the pass – was probably in the 30's at the pass and blowing hard (40mph winds?) with hail. I was wearing shorts, light windpants (which were quickly soaked), a long sleeve zipneck capilene 2 baselayer, and an OR Helium 2 rainshell. As I got higher, and it got colder I put on a light fleece hat under my sunrunner hat, midweight liner gloves, then OR Versaliner shell gloves in an attempt to stay warm. I was exerting myself plenty, and the rainshell kept my head and torso dry, but my legs and hands were soaked and my hands were getting numb, and I was getting colder. I was using trekking poles, and the gloves are not seam sealed. Knowing that I needed to maintain use of my hands in order to stay safe, I decided to put on the only additional layer that I had, which was a patagonia ultralight down hoody. There was a risk of it getting wet but I just had to make it over the pass and down and I knew I could warm up. I was worried that I might not be able to zip my jackets up, but I put the down jacket on while I still had enough dexterity so it worked out fine. Had I waited longer I'm not sure I would have been able to do so.

The down jacket stayed mostly dry under my shell and I got over the pass (11,800 feet). I was still cold when I reached the trailhead but not dangerously so.

You can definitely get hypothermic while exerting yourself in the mountains, even in midsummer. IMHO it is better to put on the extra layer (or set up a shelter and warm up) BEFORE you get hypothermic and lose the ability to operate zippers, set up a shelter, etc. because once that happens you are pretty screwed.

Roger: “Can you provide any published statistics to support this rather strange claim?”

Rather well known and accepted fact here in the wet PNW. Much anecdotal evidence around these parts. Many people contract hypothermia while hiking, climbing, sking, ect here in the PNW. As for scientific studies simple Google search will turn up a lot of information. Here is one among many – chosen because it addresses hiking specifically:

http://www.ncbi.nlm.nih.gov/pubmed/8889744

“We conclude that if a person can tolerate the intense discomfort of prolonged wet-cold exposure, he or she has the potential to resist significant core hypothermia for at least 4 h of walking under the conditions of this experiment. Exceptions to this generalization occur, making exposure of < 4 h a hypothermia risk for some individuals. Exposures > 4 h would involve increasing probability of rapid decline into hypothermia, associated with exhaustion of shivering and exercise heat production.”

A couple more:

http://europepmc.org/abstract/med/9451529

http://runnersconnect.net/running-training-articles/running-in-cold-weather/

“A 1985 study, also by R.J. Maughan, demonstrated the effects of race strategy on hypothermia during cold-weather racing. At the 1982 Aberdeen marathon in Scotland, 59 volunteers had their body temperature measured immediately after finishing the race. The weather was cool and blustery, with a 50-degree air temperature and winds of 16 miles per hour.

Though this is relatively modest weather by most runners’ standards, there were nevertheless several runners with temperatures significantly below the normal range.”

If marathon running does not qualify as exerting ones self I don’t know what does!

http://www.hypothermia.org/weinberg.htm

This last one is more general, but has a long list of studies and papers on hypothermia at the bottom.

I didn't mean to start a debate. And I'd rather people error on the side of caution.

But… my point is that people frequently put on more layers than they need while moving. They get those layers wet and then when the stop they have nothing dry. That leads to flagging moral and people uncomfortable tend to make compounding mistakes and ultimately that leads to a more dangerous situation than does being a little chilly while hiking and your body is generating lots of excess heat.

So… I'm not talking about the hail storm deluge in high wind that happens and you are obviously cold. By all means put on appropriate layers and find suitable shelter. I would think that would be obvious for anyone in that situation. Even if you get cold rain over duration with high winds….by all means seek greater comfort by layering up. But don't think that you need to reach into your pack every time you get a little drizzle while it is in the 30s or 40s.

Kev – agreed. The studies cited above make sense to me too. The human body can compensate under adverse conditions for a while – the amount of time will vary greatly depending on numerous factors obviously – but at some point even with continued exertion people can decompensate quickly.

That NCBI study is interesting. 7.4cm/hr is Noah style rain in my book! Considering the American Meteorological Society classifies 0.76cm/hr as "heavy rain" maybe we can assume it's a typo? Not to be pedantic, but any published article that has such an egregious order of magnitude error in the abstract is suspect.

That said, I've experience 8+hrs at elevation without rain wear or shelter. I experienced everything from snow, to hail, to cloud mist. I was basically drenched the entire time. Any stop over 10s had me shivering badly from the cold. Thoughts of your own mortality are VERY sobering. I don't know if I was lucky or just stubborn but that day could have ended much worse than severe shakes while warming up in my car. I do know this, I'll never let it happen again from poor planning.

Hypothermia is scary when you don't have an easy exit strategy. Always err on the side of caution until you've thoroughly tested your paper schemes. Some ideas don't translate well outside of controlled experiments, just be cognizant when you're pushing the envelope of your experience, and have an exit strategy!