I think it should be because of the heat generated, you need to check in to that and may be because of the quality of the cables too. Thanks for sharing some useful tips to all.
People who work with networks think of them in terms of layers. These layers include the Internet, your modem and router, and the computer (or computers) on your network. To troubleshoot a problem effectively, you must first identify which network layer is causing the problem. Visit the network cabling help
I agree. Avoid using low quality cables, it could turn your data center/business into a pile of ash if due to faulty wiring brought by the melted cable wires due to heat/high temperature. Or, been nibbled by some nasty rodent or something.