Mammals can also generate little bursts of heat by shivering, and most mammals can be active even in cold weather because they are warm-blooded. Given these facts, which can help warm-blooded animals stay active in cold among the following options:
- shivering
 - four limbs
 - Animal fur
 - sleep
 - sweating
 - hibernation
 - cold blood
 - fur seals


 

 shivering        