Making existing gear as warm as possible

[beean]

It's the drop in o2 saturation in your blood that affects you. When you head up to 1500m from sea level the saturation only drops by 3% or so, depending on your respiratory rate (which the body automatically adjusts to account for this) and other factors. The drop in o2 pressure is indeed around 20%, but this doesn't affect us too much, possibly because there's more than necessary o2 in the atmosphere? Is there a doctor in the house?

I do agree that it affects everyone differently, I have friends that get hit hard by altitude and others that seem to power past the 3000m mark where I start to get a sore head.

[Orion]

1500m is where most athletic training takes place here and where the hypobaric tents are set to.

Where did you get that? It sounds suspiciously low to me. In fact your first link says 2000-2500 meters.

According to wikipedia, the hypo-oxygen "altitude" tents are typically set to simulate 2500m or higher.

At 1500metres oxygen is at 80% of that at sea level, 20% is quite a drop

I think the 80% level is a little bit higher, but you're right, it should make a measurable difference in performance. It's just not one that I have ever noticed while hiking vigorously or during strenuous rock climbing. I feel like I am 100% at that altitude.

[Moondog55]

The 1500m for the hypobaric tents came from a football club website
Falls Creek village and the lake just happens to be at around 1500 metres and so that's where the athletes train.
Normative mean sea level air pressure here is 1.06bar
1500m is 0.84bar; I took this to mean 80%
Personally I found a huge difference between 1500m and 2200m [ I went from Falls Creek Vic Australia to Mt Hagen Nuigini] but when we went right into the highlands to climb some peaks i got into trouble at 4000

[Alittleruff]

What about adding a few of those pocket warmers that are activated by snapping them. Use them inside your sleeping bag if you get really cold. Can't hurt. Takes up very little room. Have a great trip. xxx

[Moondog55]

Most of us regard those little chemical heaters as emergency use only gimmicks. The ideal is the be able to cope with the absolute worst the world could hit you with, without resorting to those, with what you carry. I've tried taking them and found they go off in storage before I have ever needed them
I know that a lot of resort skiers use them; tho I think that is because they do not dress properly / warmly enough

[Zone-5]

Buy some 3M Thinsulate fabric and use this as an extra layer...

[Orion]

Normative mean sea level air pressure here is 1.06bar

Is that a typo? The Guinness world record sea level adjusted barometric pressure is 1.083hPa 1083hPa. Even getting to 1.06 would be unusual in most places; it's not even the average where that record occurred.

In any case this only serves to confuse the point. You used a standard atmosphere table for pressure vs altitude but compared it your local MSLP. The pressure at 1500m at a location with a sea level pressure of 1.06 would be different. If you want to be precise then you'd have to include temperature, humidity, lapse rate as these have pronounced effects on the pressure/elevation. Maybe I'm just splitting hairs at this point...

But I still think 1500m sounds kind of low to worry about effects of altitude.
If you were running a marathon instead of laying in a sleeping bag it would be different.

[Orion]

What about adding a few of those pocket warmers that are activated by snapping them. Use them inside your sleeping bag if you get really cold. Can't hurt. Takes up very little room. Have a great trip. xxx

They don't have enough heat to bother.
You'd do better to carry that extra weight in either down feathers or chocolate.

[Moondog55]

That's an excellent strategy Zone-5, but the OP wants to use existing gear not buy or acquire any new stuff
I took those figure from the BOM website Orion. I'm wondering id the fact that we are the flattest continent on earth and that most of us live with-in 50 meters of sea level has anything to do with it?
Still the effects are real enough for me and hauling a 135 kilo sled train 10 kilometers is more than equal to running a marathon IMO and I've run a marathon or three in my youth

[Orion]

I took those figure from the BOM website Orion. I'm wondering id the fact that we are the flattest continent on earth and that most of us live with-in 50 meters of sea level has anything to do with it?

I looked at some of the BOM historical data and while Australia does appear to have higher than average adjusted sea level pressure values it doesn't come close to 1.060hPa 1060hPa.

Here's the current map, courtesy of BOM:



You can get BOM to give a nice 7 day animation.

I'm not sure why Australia seems to be higher on average. I wouldn't think that proximity to the actual sea level is that important. I live within 70m of sea level but the average here is unremarkable. The record holder for maximum sea level pressure is Siberia, at 261m ASL, during a period of extreme cold.

Still the effects are real enough for me and hauling a 135 kilo sled train 10 kilometers is more than equal to running a marathon IMO and I've run a marathon or three in my youth

I see, I didn't realize you were doing that sort of work. I've never hauled 135kg of anything anywhere, not that I recall.

[Moondog55]

Hmm Not sure now if i read it correctly or not
What's the conversion for hectopascals to BAR?

[Orion]

What's the conversion for hectopascals to BAR?

I was putting the decimal in the wrong place. 1hPa = 1mbar or 0.001bar.
So 1.060bar = 1060hPa.

At this point I'm more interested in your method of bushwalking that involves 135kg sled loads. (!)

[Moondog55]

I think I may have missed a zero
1.006 bar makes a lot more sense?
I ski and on occasion I can afford a seasons lift pass
Camp is 5 klicks from the first run so I camp out and skinny in each morning
I drag my base camp stuff in to the camp site in the National Park and that weight was for the year before last when I didn't have a chance to drop everything off prior
It involved a bit of leapfrogging too
I also had some excess gear as I was experimenting with a large but cheap tipi and had my touring gear as well

[Orion]

1.006 sounds a little below average. The standard atmosphere sea level pressure is 1013.25hPa. It really does look like Australia has higher pressure in general, just from looking at a number of months of averages on BOM. That's not very scientific but I think I got a good impression of it. Not sure why it's that way.

[Ms_Mudd]

Bumping up this old thread instead of starting a new one. I have trawled through the forum and read all the relevant threads I can find on this topic.

I am taking my 11yo out for her first multiday walk in Autumn (Southern NSW), the Winter bag she stays warm in for car camping is 1.8+kg and rated 0c, she has slept comfortably in this overnight when the ground has been frosted the next day. It is an Aldi job. The other Aldi bag she has is a Summer one, it weighs 750g and is rated to 11c. She is nearly as tall as I am, although is a bit of a string bean, so lengthwise needs an adult bag. What I am seeking some forum wisdom on is can the Aldi Summer bag be boosted to take on our upcoming trip?

I imagine I will be a good mother and I will use the boosted bag and let her use my -8c down bag which I am always toasty in. I am a cold sleeper. I on sold my -12C quilt not long ago as I still froze at 0C with it and all my clothes on.

One thought was to make a little quilt out of a crappy synthetic sleeping bag which I would source from the opshop, or to buy a chinese down quilt or summer bag to either put in the bag or over the top. Or a polar fleece quilt or liner?

My main objectives would be to (safely!) save on expenditure, packweight and packed dimensions as I will be literally shouldering most of our load as she will only feasibly be able to carry 5kg.

Feel free to tell me to cough up the funds for a decent bag- I just figured that I would see how she feels about walking before buying gear. Like I did with my now totally enthused and regular bush go-er 22yo son.

Edited to add; Will be taking ccf to boost warmth also, have a lovely lightweight bit here courtesy of the very kind Moondog

[Lamont]

https://www.massdrop.com/buy/massdrop-pine-down-blanket
Check the discussion (https://www.massdrop.com/buy/massdrop-p ... iscussions) for the quiltish use.
540 grams total weight, 300 grams of RDS down at 850fp. $150 delivered.
With clothes and Uniqlo/Decathlon down jacket, rain coat and ebay wind pants ($20) over leggings-potential for the kidlet to be warm down to 5 to 7 maybe ?
You probably have most, give me yell if you want some champion stretchy windpants (above) at about 70 grams. I've used them around camp in shorts down to 0.
When the nipper finishes with the quilt you can use it in Summer.
Any good Muddy?

[Ms_Mudd]

Ahh Lamont, my good ol Massdrop buddy I have made two very sound and well-used purchases on your MD recommendation.
Nice weight for the quilt, pretty reasonable really and equivalent in price point to what I have been browsing on Aliexpress. Gosh, I wouldn't expect a loan of a bit of gear, I have been very fortunate to get some lovely gear through the forum already through the Marketplace- it never fails to deliver. If you say the quilt is worth the purchase, that is good enough for me.

We had a fashion parade tonight -think she was delaying bedtime as much as being excited about our walk- and we have about all we need, just need some tights or quick dry pants for walking and we are done. Thanks for offer of the windpants, I nabbed some on ebay last night 2nd hand and hopefully they will fit.

[Lamont]

No worries. Maybe check the discussion page I linked and or the reviews. It seems to be fine, nearly bought one myself, I think with wearing the down jacket(if needed) leggings etc it should be fine from other users have said. BTW check out Uniqlo thermal leggings in 3 temp/weights. Often on sale. My PJ pants. Cheers.

[Huntsman247]

I've found that hand warmers can boost a bags warmth. They last 5-8 hrs depending on the type and 2 or 3 will get you through the night. Sort of like an electric blanket.
I used to use them ages ago when I was first starting out. I had a cheap bag of eBay that's basically a summer bag keep me warm in -5.
They are only single use though but are all natural so you can burn them if you have a fire. I wouldn't use them if you have super thin synthetic materials though as they get a bit hot.
Not the most even heating obviously but good enough.

[Moondog55]

I have a very warm kids bag you can borrow, for as long as needed.

viewtopic.php?f=13&t=6166&start=150

Otherwise I could sell you some Thinsulate and you could make an overbag or an overquilt.

[ribuck]

Feel free to tell me to cough up the funds for a decent bag

I will just say that the best birthday present I ever received was a good down sleeping bag on my 13th birthday. I used it for years for sleepovers and car camping before I discovered bushwalking, then for hundreds of nights in the bush before I started snow camping and felt the need to upgrade.

[Ms_Mudd]

She may yet get one for her 12th, if she plans on coming out walking again Otherwise, her Aldi car camping bag will need to suffice. Incentive to keep walking? Bribery? bahahaha