The main reason for such leaf fall and such hibernation is lack of water. If there was enough water, then both plants and animals would easily tolerate the temperatures that are characteristic of these regions. Having lost their leaves, the plants stop photosynthesis, but they remain alive and do not dry out. The same system in animals: in hibernation, they survive the heat and retain water.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.