I was reading that temperatures on the Eurasian steppe can get as low as -55 C during the winter. I imagine the nomadic people who lived in this region could deal with this by wearing warm clothing and living in portable felt dwellings like a yurt or a ger. Settled societies could build barns. But for Mongolic and Turkic tribes who depended heavily on horses (lacking the thick wool or other cold weather adaptations of, say, sheep), how did they keep the herds from freezing to death during the winter? Did the horses have their own tents? Are steppe horses just way more resilient to extreme temperatures? Did they knit them little sweaters? Light bonfires - which seems really unsafe in the middle of a grassland?
The short answer is that basically the horses took care of themselves.
It's worth noting that Mongols, Kazakhs and other nomadic and pastoral Eurasian steppe peoples used, historically and in the present, special breeds of horse, usually the steppe horse that are incredibly hardy, as they would need to be given that the steppe easily goes to 40C in the summer and -40C in the winter (although it should be noted that both of these extremes are, well, extremes, and represent heat waves and cold snaps, not the baseline summer and winter temperatures). For the winter, steppe horses in particular have a dense fur coat that helps them survive the cold. Steppe horses also tend to have strong, wide hooves that allow them to kick and dig through snow in order to eat grass underneath.
However, it's not as if nomadic peoples were free of the danger of losing livestock to the weather, sometimes catastrophically. These dangerous winter conditions could often cause the deaths of millions of livestock (at least in the modern cases where we have a sense of numbers), and are known as zhut in Kazakh, and zud in Mongolian. What might surprise readers is that these dangerous weather conditions were more likely to occur in the late winter/early spring than necessarily in the dead of winter, although bad conditions could of course strike at any time. But the most feared conditions tended to be when there was a slight thaw or rain and then a sudden temperature drop, which caused an unbreakable layer of ice to form over the grass that herds would usually feed on.
A last point to remember is that Eurasian nomads had seasonal pastures, and winter quarters tended to be at lower elevations and in more sheltered locations than summer pastures. A nomadic clan therefore wasn't out on the middle of the steppe in the dead of winter, but more likely in a river valley. By the 19th and 20th centuries, at least in Kazakhstan, these winter quarters included permanent stone buildings and fodder crops raised as supplemental winter fodder.