Overheating and 72X Router

We had a failure on a 72x SDI router. We believe it's an overheating issue. This is in an ATA 36 RU rack with undressed cabling.
The router locked up and no control. The router panels had a red blinking light on button 1. We recycled power and it came back. I see a heat reliability issue.
Is a fan required on all routers? Is there a thermal diagnostics display in the software to monitor this. What is the max operating temp?
Please advise,
Gary
The router locked up and no control. The router panels had a red blinking light on button 1. We recycled power and it came back. I see a heat reliability issue.
Is a fan required on all routers? Is there a thermal diagnostics display in the software to monitor this. What is the max operating temp?
Please advise,
Gary