TINFOIL hats may protect the brain from dangerous radio frequencies and mind-control rays. Or they may not, according to a group of students from the Massachusetts Institute of Technology, who tested three standard designs with equipment costing $250,000. They found the foil actually amplified some radio signals - especially those on frequencies used by the US government - by a factor of up to 100. In summing up, they say: "It requires no stretch of the imagination to conclude that the current helmet craze is likely to have been propagated by the government, possibly with the involvement of the FCC [Federal Communications Commission]. We hope this report will encourage the paranoid community to develop improved helmet designs to avoid falling prey to these shortcomings."

Of course the real problem with the classic tinfoil hat is that wearing one makes you look like a nut. Now Less EMF, a company in Albany, New York, allows you to play safe with more style. It makes a line of clothing woven from thread with a core of copper-silver wire that provides electromagnetic shielding (www.lessemf.com/personal.html).

With a baseball-style cap woven from the fabric, you can "provide your brain a quiet place without interference to your mental processes from RF radiation", the company's website says. At $29.95, it costs much more than a roll of aluminium foil, but wins hands down for style. For protection at work you can buy a shirt woven from metal-core thread for $89.95. If your budget is tight, Less EMF also offers shielded undergarments - best worn over standard cotton ones to keep the conductive fabric from touching your skin. A camisole is $38, boxer shorts and T-shirts are $64. And for a worry-free night's sleep, you can shield yourself and your bed with a $499.95 canopy woven from silver/nylon thread.