Zend certified PHP/Magento developer

Router in Closed Cabinet Okay

I know that it could overheat, but I have been having no symptoms of the router overheating. The router is a travel router and it has plenty of room inside and the cabinet has some vent holes where the door closes, little cracks.

Is it a high possibility that the router is overheating and having heat issues without me knowing? I have been opening up the compartment and putting my hand in and the air feels normal. Should I be concerned, would the air feel hot if it were to be overheating?