Router overheating in cabinet installs

Routers and modems installed in sealed cabinets without ventilation run hotter than manufacturers design for, which can cause random reboots, reduced range, or shortened lifespan over time. These units generate real heat under continuous use and most aren't designed to be fully enclosed — a few small vent holes or a low-profile fan makes a real difference. Is the current install fully sealed, or does it have any airflow?