Reptiles sit in the sun when they are cold and in the shade when they are hot, for example: reptiles such as lizards and snakes. Other animals do not try to change their body temperature at all, for example many worm-type animals living in the sea.
Some insects control their temperature, especially colonial insects. Termite mounds have 'air conditioning': their system of openings and galleries allows currents of air to flow through the mound. Honey bees fan their wings to cool their colony.
Animals whose bodies control their body temperature are called warm-blooded.
The correct scientific word for cold-blooded is poikilotherm (noun), poikilothermic (adjective). They are not actually cold-blooded, it is that they live with a much wider range of body temperatures than homeotherms (warm-blooded animals).