Why can’t turtles, crocodiles, lizards live in cold climates?

The fact is that these animals are cold-blooded. This means that their body is not able to maintain a constant body temperature in different climates. Because of this, their body temperature is completely dependent on the ambient temperature. If the ambient temperature rises below zero on the Celsius scale, then this can cause death of the animal, since this temperature causes the water to crystallize in the cells and their destruction due to this. Therefore, animals are forced to hide and fall into suspended animation.