lol When it is cold enough, body starts to shake, each muscle is convulsing, consuming glucose and making it into heat. Brains use a lot of power that comes f

lol When it is cold enough, body starts to shake, each muscle is convulsing, consuming glucose and making it into heat. Brains use a lot of power that comes from methabolism. Could it be that human body tries to warm itself using brains to utilize glucose by doing cognitive tasks? What cognitive tasks are most energy consuming?