Most businesses house IT infrastructure equipment in small server rooms or wiring closets to keep it out of the way – but typically these areas are poorly ventilated (unless custom-built) and often unsupervised.
The door should be kept locked for security reasons, but remember that heat is the enemy of electronics. In fact, many manufacturer warranties can be voided by operating equipment at temperatures in excess of 85 degrees Fahrenheit.
The simplest solutions involve both input and exhaust fans as well as air conditioning. Fans can be placed above or below racks, or in front of and behind racks. Typically, one fan will blow cool air in and another will vent hot air out. In many cases, central air conditioning can be augmented with a spot-cooling solution.
How do you know if temperature is properly controlled, doors are locked, and equipment is safe from theft, fire, and water? A number of network-attached devices include sensors for environmental monitoring and physical security. Devices from companies like AVTech and APC monitor power, temperature, humidity, airflow, and just about anything that you can make a sensor for. There are even probes to tell you if there's water on the floor. In many cases, it is better to get something oversize and grow into a solution than it is to choose a small one and then have to rip it out and replace it.
Establish a standard alert procedure with escalating notifications. For example, when the temperature in the server room reaches 80 degrees Fahrenheit, alert the network engineer; when it climbs to 85 degrees Fahrenheit, alert the IT manager; and when it climbs to 90 degrees Fahrenheit, alert the business owner.
Alarms and notifications can often be programmed into software that comes with the device or the device itself. Larger organisations will want to use SNMP network monitoring software to keep track of these devices and their error conditions. It may be possible to launch a scripted response to an error condition, such as performing a clean shutdown as soon as water is detected.