In one embodiment, a method includes receiving an indication at a modular electronic system of initiation of online removal for a module removably inserted into a slot of the modular electronic system, increasing a fan speed at the modular electronic system before the module is removed, monitoring an internal temperature at the modular electronic system, and providing an indication that the module is ready for removal upon reaching a specified cooling state at the modular electronic system based on the temperature monitoring. A panel on an adjacent module is opened and extends into the slot upon removal of the module to substantially block airflow bypass from the slot and maintain cooling within the modular electronic system. An apparatus and logic are also disclosed herein.