solo sailors (amongst others) do this; 30-90mins of sleep each time, but they cat nap all the time, not just once a day. However, research shows that long term

solo sailors (amongst others) do this; 30-90mins of sleep each time, but they cat nap all the time, not just once a day. However, research shows that long term learning etc, as well as critical decision making, are impaired. My anecdata of 1; I prefer 6-7 hours of sleep, but during some expeditions, I'd be lucky to get 2-3 hours before a summit attempt of 12-18 hours (leave at 1-2am, return to high camp by 3-4pm, pack up and head down to a lower level for safety). For safety, I make sure to practice all the skills required (rope, carabiner and knot handling) so these are "routine", and not require more cognitive effort to "figure out". A funny story during an expedition: a friend couldn't lift his foot whilst we were all preparing for some ice traverse - it was stuck for some reason, we all stood around wondering why, and we finally realised I was standing on one of his crampon straps. I swear it took us 10mins to figure this out, a result of sleep deprivation, high elevation, being swathed in layers of clothing, and general fatigue.