Q. We have been advised by our hardware support person to switch off the computers in the practice during lightning/thunder storms. Is this really necessary? What are the risks?

A. Apart from installing a lightning rod, it is not possible to protect against direct lightning strikes on a building. Therefore, the people, the computers and the structure of the building are at risk. More often, lightning will strike nearby and a surge will come through the electrical system or phone wires. It is this surge that commonly damages computer equipment. True electrical surges, where the voltage rarely exceeds 25,000 volts, are much simpler to protect against than lightning, where the voltage can reach 50,000,000 volts. An unprotected computer that experiences a power surge will typically have its network card, video card and motherboard fried. If you are lucky the hard drive will be spared. Even if the hardware is not damaged, a sudden server crash due to an electrical surge can lead to corruption of your practice database and cause you all kinds of problems with data loss and corrupted data. Over the last few years, I have lost a dial up modem and an ISDN box to lighting, and many people relate similar stories. Here is how to protect your computers and network:

• Ensure you have a UPS (uninterruptible power supply) for your server, monitor and router. This protects the server from surges and allows you time to shut the server down in a controlled manner should you lose electrical power. Plug your UPS into a surge protector and then into the socket.
• Ensure you have surge protectors for all of your computers, laptops, printers, scanners and backup drives. These protect the equipment from power surges. There is a difference between a power extension strip and a surge protector. A good surge protector is worth the extra money.
• Ensure your telephone lines and broadband pass through a surge protector. Surges coming in on telephone lines are a common cause of problems.
• Ensure you have regular backups of your data, at least daily, so that should you experience damage you will be able to restore your data.
• If you don't have UPS and surge protectors, then shut down your computers during a thunderstorm and disconnect them from the electrical sockets and the phone or broadband cables.
• Pray. Lightning is a force of nature. According to Wikipedia, lightning rapidly heats the air in its immediate vicinity to around 20,000°C; about three times the temperature of the surface of the sun.