You can tell if your projector is about to overheat because the projector will be really hot. If it does overheat, the projector will shut itself off. If this happens, unplug the projector for 15 minutes, and then try again. If this continues to happen, there might be something wrong with the fan. Make sure the fan vent on the side of the projector is not blocked or clogged. If you need to clean or replace the fan, check out this repair guide. Merch Source Projector Entertainment II Troubleshooting