Emergency shelters?

Yeah. The high flys are why some aren’t great in exposured weather. But many also have designs which allow the fly to pitch low or high easily. Again, if one wants to compare with a tarp you can simply open a door. You’re generally no more exposed than most tarp pitches with pretty comparable air flow. Tarps are a nightmare in sandfly country. I’ve had such a quantity of sandflies converge at the point the fly met the mesh, that the pressure forced some through the tiny “midge proof” holes one night in the Nelson lakes!

Picked up a Durston X-mid that is the best design I've seen in about 20 years, it's a modified 'mid' with two peaks, off-set poles and the genius is that you sleep on an angle, which provides dual doors, large and high vestibules. Mine weighs 950 grams with all guy ropes and 9 pegs. If you wanted to focus more on 'emergency' which I'm guessing means you don't plan on using it, then I would go with a simple tarp and bivy setup, for example Enlightened Equipment, Yama Mountain Gear and Mountain Laurel Designs all make really nice wind/bug bivies that weigh around 230 grams, and if you combine that with a basic A-framed, 9 ft long tarp, you'll be looking at another 350 grams or so, then add another 125 grams for pegs and you're at 700 grams for a much more versatile sleep system than a ultralight tent. For example on nice, cool nights you can just sleep under the tarp, or on wet rainy nights simply add the bivy for complete protection, but can also use the bivy in a hut for extra warmth or when infested with sandflies, etc... Durston X-mid - https://durstongear.com/product/x-mid-1p Tarps / Bivy / Net Tents - www.yamamountaingear.com Bivy - https://enlightenedequipment.com/recon-stock/

The x-mid is my one person tent :) When bugs aren’t a problem I normally use my “splash” bivy (ie it’s not fully waterproof) in combo with a 350g-ish pyramid tarp. It’s a light enough set up. Around 500g. The hesitancy I have with it is that in a genuine emergency situation there’s a good chance I’m injured or impaired somehow, and fluffing with trying to get a tarp up seems like it could be escalating the scale of emergency - especially if there wasn’t enough suitable ground to pitch.

"especially if there wasnt enough suitable ground to pitch" I'd think in that situation a tarp would be preferable to a tent. You can get (imperfect) shelter from a tarp in almost any situation. Whereas a tent in thick scrub or boulderfields is 100% useless.

Agreed. I had a pyramid shaped tarp which is nearly as limited as a tent where it comes to imperfect ground, as it relies on good placement of the corner stakes. I guess a simple flat tarp would be more versatile (if not more hassle to get right). Again a bivy seems like a winner here.

I think there are a range of solutions depending on the situation you're going into and whether you're on your own or not. At one end is just taking a mylar survival bag. Cheap and light and will probably save you well enough although not particularly comfortably. Take two if going on wintery tops - in an emergency, sleeping bag goes in one, other goes in sleeping bag, you go in it. Sleeping bag stays dry from outside and doesn't get wet from you on the inside. You'll likely end up warm even in windy, snowy tussock if you can sit on something insulating like your pack. Problem is, it's not a particularly pleasant prospect, so you'll likely try to keep going for the hut, cross that dodgy river rather than spend that unpleasant night outside. At the other end is taking full alpine tents for all in spite of hut plans. I think a good solution somewhere in the middle is to take the fly and poles from an alpine tent that can pitch with just the fly. The fly from a Macpac Microlight will shelter one or two, a Minaret fly would shelter up to three or four in a real emergency. Carry a mylar survival bag as well, use it as a groundsheet if necessary. That way, you've got a reasonably comfortable option for one or two, if two you are gaining a lot of warmth if you are huddled together rather than in separate bivy bags. If you are on your own and injured and unable to get the tent fly up, the mylar survival bag and the fly wrapped around you should keep you OK. I carry a mylar poncho that only weighs about 50 g. I figure if injured in a way that makes it difficult to get in a bag, I can get it over my upper body and keep a lot of heat in my head and torso. So for me: Daytrip or definite plans to stay in a hut and minimal chance of needing to camp out outside of a serious injury: Mylar survival bag and poncho. Using huts but want a reasonable plan B option if I get delayed, geographically embarrassed, stuck on the wrong side of a river or similar, or am going with the kids: Fly and poles from the solo or two person alpine tent, plus mylar survival bag and poncho.

That sounds like a good set of solutions. And a good point re: minimal "emergency" shelter (e.g. mylar bag) potentially being a catalyst for dangerous decision making. I've read about some people carrying a tarp with the plan of just wrapping themselves in it, if things turn south. Whether that is genuinely adequate shelter is another question (e.g. if the inevitable moisture build up from sweat would be a serious issue in certain conditions). Although combining that with a mylar blanket inside the sleeping bag would be a good option (you suggest using two mylar blankets, though this would do the same). If you've got the tarp then you have the potential to at least pitch one edge off the ground for some relative improvement of comfort and air flow, and plan c is just wrapping oneself. The double mylar blanket concept is interesting. I've seen that very cold weather adventurers often use "vapour barrier liners" in clothing and sleep systems. Basically a next-to-skin layer which traps your sweat next to skin, so your clothing and sleep layers don't eventually soak and freeze from body moisture.

I believe you need to be self sufficient with shelter on a tramp but relying just on a PLB if you land up in the zoodoos is problematic.If you are injured in foul weather,a helo wont be able to fly.Being wet and cold is life threatening & a an emergency shelter might save the use of a body bag.

Yeah, I don't think many people are really relying on PLBs, per se. I've read (speculative, unprovable) claims that people are more likely to make risky decisions if they have a PLB, or other satellite communication device. But I personally struggle to imagine that anyone would intentionally make dangerous decisions with the concious rationale of "ah well, if you get swept down the river I'll just get air lifted out of this nearly-impossible-to-access-by-air gully." I think that perception probably comes from the increased number of people accessing our bush and mountains (good) without enough experience or skills (bad) and taking advice on gear etc from Kathmandu staff in place of learning skills from experienced trampers (bad). More people = more rescues, especially when there's probably a higher proportion of inexperienced people. I think it's also perpetuated by the quick and more abundant nature of online journalism, and low quality journalism. Comments on facebook threads of stuff.co.nz articles are alarmingly cruel and judgemental given the scant and poorly reported info in those articles. Personally I treat a PLB as an extension of leaving my intentions with family members and in hut log books, one that will potentially lead to a faster rescue - if I'm 12 hours late for when I was meant to check in, that may mean I've been trapped by a creek with a broken leg for 12 hours before alarm is raised.

PLB do give the option of calling the cavalry. This might not mean you take that flooded river any less seriously but it could easily mean that when you get to a marginal river and know the forecast means it should be lower not higher when you come back you are more likely to carry on. If the forecast was wrong before it would mean you were stuck but now you have a get out of jail free card