cat's body temperture

I don't know if this is the right forum or not for this question;

How do you tell if a cat is too cold or too hot ? Should I put Bella & Thunder in front of a fan ? They are not pantting or anything.

Kitties don't pant to cool themselves off like dogs do.  If you're concerned that they might get overheated, then you could always run a fan for them.  Most kitties will seek cool places such as tile floors or ceramic sinks and bathtubs to cool off. 
 

Are they inside, outside or in a kennel? If it's comfortable for you, it's probably comfortable for them, as long as there is air movement and they can get out of the direct sun.