Answer:
When it is cold, shivering causes the muscles to contract and produce heat.
Explanation:
Our body always maintains homeostatic conditions. Homeostasis is to maintain a stable condition inside the body against any changes in the surrounding environment. One of the best example of homeostasis in our body is regulation of normal body temperature. When ever its cold, our body tries to maintain the normal body temperature by causing the skeletal muscles to shiver. Shivering of skeletal muscle is nothing but vigorous contraction of muscles during which heat is produced. Contraction of muscles is an endergonic process which required energy and produces metabolic heat as a byproduct. This is a negative feed back mechanism in our body. Excess heat due to vigorous or sustained skeletal muscle contraction can heat up the body to such an extent that the other metabolic reactions in our body get affected, which is not good.
