How Heat Stayed After the Fire Died

How did heat stay after the fire died? The ground under a cold sleeper, a grass bed, and a body that learned the night. A fire heats one side and leaves the back cold. Sleep makes the chill worse, because shivering nearly stops. Hunter gatherer nights, stone age cold, a reindeer hide, heated stones, and a desert test from 1958 are the story. Border Cave bedding, brown fat, snow shelters, and the Pit of Bones are in it too. All research and sources are linked below. 00:00 The rock 01:05 The fire 02:27 The drop 03:34 The ground 04:05 The bed 05:50 The curl 07:27 The test 09:55 Two climates 11:03 The snow 12:01 The bones RESEARCH & SOURCES P. F. Scholander and colleagues, "Cold adaptation in Australian aborigines," Journal of Applied Physiology, 1958. https://journals.physiology.org/doi/1... Europeans shivered. The Pitjantjatjara slept, with the feet allowed to cool. The spoken twelve to fifteen degrees is that paper's range, told in round numbers. A later night in the same desert work is Hammel and colleagues, Journal of Applied Physiology, 1959. The video treats the pair as one test. A separate stay put Norwegian men outdoors for about six weeks near freezing. After it they slept better in the cold. That is acclimatization, not a trait you must be born with. The episode does not pin that stay to one page. Lyn Wadley and colleagues, "Fire and grass bedding at Border Cave," Science, 2020. https://www.science.org/doi/10.1126/s... Grass on ash, about 200,000 years ago, in a place that almost never freezes. The thirty-centimeter thickness is the layer as described. Reindeer hair is widely described as hollow. Northern groups still rate the hide highly as bedding. This episode does not cite a single lab that measured every hair. Heated stones under bedding are described among several northern groups and in survival notes. There is no one invention date. The claim that half of body heat leaves through the head is a myth. The head loses about as much as another part of the same size. A hood helps because the head is the part left bare. Brown fat that makes heat without shivering, and cold that makes it more active, is in Wouter van Marken Lichtenbelt and colleagues, New England Journal of Medicine, 2009. https://www.nejm.org/doi/full/10.1056... Arctic groups are reported with a higher metabolism and a diet heavy in fat. Ice-age Europe is read here as that pattern, not the desert pattern. Eating before sleep is the practical habit that follows. Antonis Bartsiokas and Juan Luis Arsuaga, "Hibernation in hominins from Atapuerca, Spain," L'Anthropologie, 2020. The Pit of Bones, about 430,000 years ago. The authors called the idea bold. Critics, including a 2020 note in Archaeology Magazine, point to ordinary seasonal hunger and to how lightly a large animal can cool. Most researchers stay cautious. The episode says a full winter sleep is unlikely. PEOPLE & SITES MENTIONED Pitjantjatjara, central Australia. Small fires, a low windbreak, sleep on the ground. Border Cave, South Africa. Grass on ash, long before frost was the problem. Sima de los Huesos, the Pit of Bones, northern Spain. Neanderthal kin, odd lines in the bone. Reindeer hide, snow shelters, and a huddle. Tools for a night that does not end at dawn. Next, another ordinary problem from the days before farms. Animation by Before Farms #AncientHumans #IceAge #StoneAge #Archaeology #HumanEvolution