Thermoregulatory response activated by cold is-

* In cold environment, muscular contractions are increased and there is increased heat production Increased muscular contraction can be due to: 1) Increased tone of muscles. 2) Voluntary activities like foot stamping, hand rubbing, spoing activities etc. * Hypothalamic stimulation in cold environment brings about the following effects which help against cold- 1) Cutaneous vasoconstriction. 2) Shivering (involuntary muscular contractions). 3) Horripilation / Piloerection (standing up of body hair). 4) Adipose tissue lipolysis (generates heat).