Shivering occurs when many muscles contract a little bit all at once, and heat production is increased by shivering and non-shivering thermogenesis . Given these facts, when many muscles contract a little bit, simultaenous, it produces: among the following options:
- forces
 - heat
 - cold blooded
 - sweat
 - electrical energy
 - Energy
 - pain
 - thermal displacement


 

  heat       