kravietz 🦇 on Nostr: I’ve just spent three days in a pleasant cave camp with with the fine folks from ...
I’ve just spent three days in a pleasant cave camp with with the fine folks from Chelsea Caving Society. The pleasure was only slightly disturbed by the fact that my sleeping bag got soaked wet on the way to the camp, which also was not fun, because it consisted of 3 hours of crawling in a rocky stream, frequently going through boulder chokes and thus quite exhausting.
With an ambient temperature of 8°C and 100% relative humidity it wouldn’t be long before I would get hypothermia with my caving over- and inner suit also being totally wet after the crawl. Fortunately apart from a sleeping bag I also took a Blizzard rescue bivy bag which I didn’t really plan to use, but it literally saved the whole trip - I was able to sleep in it two nights in relative warmth.
In a cave everyone carries a “space blanket” which is a thin plastic sheet covered with aluminium on one side for its heat radiation reflecting properties, but it’s a poor insulation from heat conducting. It does work where where you’re covered with it on top or sides because the layer of air prevents conduction. But where you sit on it or touch anything through it, the blanket offers nearly zero protection. If you’re in an emergency and use the space blanket, don’t put sit directly on the ground, always put something - backpack, rope, spare jacket, and only place the blanket on it. But the Blizzard has an interesting construction, where it has two layers of the “silver” lining with something between them, so when you stretch it to the sides, this something forms a kind of extra insulating layer and it does work pretty well on all sides.
Professional rescue services often use a kind of bubble wrap to insulate the casualty from the ground. Even a regular packing bubble wrap works great, except it’s too bulky to be taken to the mountains.
With an ambient temperature of 8°C and 100% relative humidity it wouldn’t be long before I would get hypothermia with my caving over- and inner suit also being totally wet after the crawl. Fortunately apart from a sleeping bag I also took a Blizzard rescue bivy bag which I didn’t really plan to use, but it literally saved the whole trip - I was able to sleep in it two nights in relative warmth.
In a cave everyone carries a “space blanket” which is a thin plastic sheet covered with aluminium on one side for its heat radiation reflecting properties, but it’s a poor insulation from heat conducting. It does work where where you’re covered with it on top or sides because the layer of air prevents conduction. But where you sit on it or touch anything through it, the blanket offers nearly zero protection. If you’re in an emergency and use the space blanket, don’t put sit directly on the ground, always put something - backpack, rope, spare jacket, and only place the blanket on it. But the Blizzard has an interesting construction, where it has two layers of the “silver” lining with something between them, so when you stretch it to the sides, this something forms a kind of extra insulating layer and it does work pretty well on all sides.
Professional rescue services often use a kind of bubble wrap to insulate the casualty from the ground. Even a regular packing bubble wrap works great, except it’s too bulky to be taken to the mountains.