Monitoring temperature within the server room is the best way to get alerted to environmental conditions that might lead to hardware failure. Overheating can cause hardware components to fail, leading to unexpected downtimes. Therefore, keeping track of temperature ensures you can take action before it reaches critical levels that could harm the equipment. Bandwidth, although important, does not provide information on environmental conditions. Similarly, CRC errors and uptime/downtime statistics are useful for other types of troubleshooting and do not directly protect against environmental dangers like overheating.