Athermal insulator slows the transfer of heat, and heat transfer fluids, such as antifreeze, protect the solar collector from freezing in cold weather. Given these facts, what protects things from freezing in cold weather among the following options:
- exoskeleton
 - thermal insulators
 - thick filling
 - a hydraulic system
 - Animal fur
 - layers of skin
 - layers of fat
 - deep water


 

  thermal insulators       