2 Baselayers for a thru-hike?

[wyattAT2005]

I've heard various people say different things about this topic, I figure I'll ask the folks in here before I spend any more money.

Some people have said that for a thru-hike you should have 2 base layers, one for hiking and one for sleeping. Any past thrus care to comment on whether this is necessary/recommended? I have an expedition weight baselayer that I've worn before in winter, I was planning on using that in cold weather, but perhaps I should use that as a sleeping baselayer and pick up a mid or silkweight baselayer for actually hiking? My departure date is March 12, and I have no plans on pushing miles.

Wyatt (as yet trailnameless)

[The Cheat]

I've heard various people say different things about this topic, I figure I'll ask the folks in here before I spend any more money.

Some people have said that for a thru-hike you should have 2 base layers, one for hiking and one for sleeping. Any past thrus care to comment on whether this is necessary/recommended? I have an expedition weight baselayer that I've worn before in winter, I was planning on using that in cold weather, but perhaps I should use that as a sleeping baselayer and pick up a mid or silkweight baselayer for actually hiking? My departure date is March 12, and I have no plans on pushing miles.

Wyatt (as yet trailnameless)
Well, I'm not a thru (yet) but as a hiker I can tell you I try not to sleep in anything I've worn that day, just because there is still sweat in it (even if it might not feel wet) and that makes me cold.

[Moose2001]

IMO, carrying two base layers is overkill. Yes, you need a good, warm base layer for camp in the evening and possibly to sleep in. This set should never been worn while hiking. It should be kept dry and ready to use when you get into camp. With a mid-March start, you shouldn't need a base layer to hike in. Most people underestimate how warm you'll be while hiking. If you get cold, put on your warmth layer or your rain gear. You'll be PLENTY warm!

[bulldog49]

I sweat alot so my clothes are always soaked when I get to camp, even in very cold weather, so I always carry a lightweight fleece and polypro shirt to change into. I keep them packed with my sleeping bag while hiking.

[Youngblood]

IMO, carrying two base layers is overkill. Yes, you need a good, warm base layer for camp in the evening and possibly to sleep in. This set should never been worn while hiking. It should be kept dry and ready to use when you get into camp. With a mid-March start, you shouldn't need a base layer to hike in. Most people underestimate how warm you'll be while hiking. If you get cold, put on your warmth layer or your rain gear. You'll be PLENTY warm!
What I do now is carry silk long johns for sleeping. But if it is freezing cold I will leave them on in the morning and then remove them later during the morning if and when I warm up. So, I carry them primarily for sleeping but they are not sacred and get put to use if it is cold enough. However, I don't think I ever heavily sweat in them while hiking since I dress down before I get to that point.

Youngblood

[Youngblood]

I sweat alot so my clothes are always soaked when I get to camp, even in very cold weather, so I always carry a lightweight fleece and polypro shirt to change into. I keep them packed with my sleeping bag while hiking.
Good point Bulldog. I don't sweat as much as some of the folks that I hike with seem to, so you probably want a different stategy if you do. It's like most anything else, there isn't one right way. Figure out a way that works for you, that is what matters.

Youngblood

[SGT Rock]

Agree, clothing recommendations can be such a subjective thing because everyone has a different comfort point and metabolism. I have known people that can run around in shorts in wet, cold weather, and I know others that feel like they are dying at 40F. Add into that acclimatization and other factors like nutrition and exhaustion, and you can get so many variations. Think back to starting a cold weather hike and what clothes you may have wanted at the start, and at the end of the hike, what you felt you needed to keep warm.

[The Solemates]

Subjective, yes, but I think its overkill to carry extra clothing to sleep in. We started in winter conditions (Feb 1) and we just slept in what we hiked in. Heres what I brought clothing wise:

Winter hiking (low temps -10F, high temps 30F):
Worn while hiking
Patagonia lightweight capilene zip-neck Tee
LL Bean lightweight 100-pile zip-neck microfleece pullover
Ex Oficio Amphi convertible pants with built-in liner
expedition weight Wal-Mart socks
Mtn Hardwear winstopper fleece hat
Wal-Mart wool/synthetic blend hunter's convertible mitts
bandana
heavyweight Merrell Grand Traverse boots
Packed
TNF 300-pile fleece jacket
Patagonia lightweight capilene long underwear bottoms
Marmot Precip rain jacket
Marmot Precip rain pants
Off-Brand 200-pile fleece socks
Waldies

I typically slept in my long underwear bottoms and my pants (lower body) and my long underwear top and microfleece top (upper body). I used my thick fleece jacket as a pillow or I slipped it on if I got cold.

I started with a 5 degree bag. It dropped below 5 degrees at least half a dozen nights while on our thru.

[chris]

As has been mentioned, this can be a very subjective thing. For coldish weather hiking (i.e, when normal temps are 45 or below), hypothermia can be a very large concern. Hypothermia occurs requently when coldish temperatures are combined with some form of wetness and wind. When you are hiking, you probably won't notice the cold as your body will be generating sufficient heat (assuming you are not on a diet as you hike). In fact, you will be sweating. If, additionally, it rains on you, you have a much higher chance of picking up hypothermia. Indeed, when you stop hiking, you've got about 15 minutes of residual warmth left over (more or less, depending on body type) before you'll start to get cold.

I like to bring some form of extra clothing with me on many hikes for this reason. For example, I might bring a full set of thermals, and then an extra fleece pullover, in addition to my down jacket. The fleece pullover gives me something that will insulate me even if it gets wet and provide enough warmth in camp should the down fail, for some reason.

In the summer time (say, May through August on the AT), I would leave the fleece at home or in a bounce bucket, but would still bring the rest.

Since you are leaving March 12, I would recommend something like:

Midweight thermals
Light fleece pullover
Insulated pullover (like down or primaloft or heavy fleece)
Warm hat or balaclava (fancy ski mask)
Liner gloves
Warm socks
Rain gear (doubles as wind protection)
Headband (sweat into this, save the warm hat for breaks and in camp)
Hiking pants
Hiking socks and shoes/boots
Hiking shirt (simple t-shirt, or long sleeve thing)

If the weather is nice, just hike in the pants, shirt, etc. If it is colder out, put on the thermal tights and either the thermal top or the fleece. If it is bitterly cold out, put both on, and the rain gear. Under no circumstances should you hike with your heavy insulation layer on. Also, if it is really cold out, you need to try to regulate how much you sweat. If you feel beads of sweat breaking out, stop and take a break.