Ferrets are mammals, so they would naturally be warmblooded. Warm-blooded means that there body heat can addapt to the temperature around them. Cold-blooded means they can only be in a certain temperature.
It is unknown whether dinosaurs were warm or cold blooded. If they were warm blooded, then small dinosaurs would have been warm blooded. If they were cold blooded, then small dinosaurs would have been cold blooded.
The difference is that cold blooded animals are warm when their environment is warm so in the morning cold blooded creatures are very slow because they are cold. Therefore warm blooded animals warm their selves up.