Question

which factors decide whether the animal is cold blooded or warm blooded

Answer 1

actually,cold blooded animals are able to adjust their temperature according to the environment whereas warm blooded animals do not have that ability to do so. examples of warm blooded animals:-human,birds etc....examples of cold blooded animals :- crocodile,turtle etc....

Answer 2

The main deciding factor in this scenario is whether the internal body temperature of an animal is constant throughout the year despite of external environmental changes (warm blooded animal) or the internal body temperature changes as the external environmental changes occur (cold blooded animal).  

As examples, all kind of mammals are warm-blooded while amphibians and reptiles are cold-blooded animals.