Humans have many responses to the cold which we use to keep warm. Some provide short-term relief, while others are more long term solutions. Our text book states shivering and metabolic increases as two of our short-term reliefs (p.422). Shivering and exercise increase the blood flow and the core temperature of our bodies. The cost is the use of energy that we must use to make these things happen. To provide the energy we must make sure we increase the amount of nutrients we intake. Carbs and fats are necessary to maintain a level of energy to keep warm in the short-term. Another short term response in humans is vasoconstriction, in which the blood flow is restricted through the veins, slowing the heart rate and keeping the heat inside the body. In the long term, humans have built fires and layers of fat under the skin to keep warm.
The largest benefit of studying humans in this manner is that we get to see how they have adapted to their own environment. We can see how different people from different backgrounds are able to individually adapt. For example, if we study the development of sickle cell in certain populations and how they build up immunities, we can use this information to help prevent or treat sickle cell in other populations.
Race is not an effective way of studying human variation because we see immigration and migration world wide. Studying a general population based on environmental factors is a more effective way of determining what will happen to people who are born into or move into the same types of environments. We can compare results with other similar environments in other parts of the world.
