It's the height of fashion, with trendsetters such as Jude Law and Ryan Gosling letting their feet go commando. Yes, it's cool to go sockless, even when wearing leather loafers. Or maybe not. There were warnings last week that the trend was linked to a rise in sales of remedies to treat athlete's foot and smelly feet. So do socks protect our feet or do they just make them sweatier in summer? And should you choose cotton over nylon, or maybe try wool?

The solution

Feet have a huge number of sweat glands – about 250,000 – and they like to use them. Our feet sweat even without exercise, but even more if you stand all day, it's hot, your feet are squashed, or you're in trainers or vinyl shoes. Cotton socks keep moisture next to the skin and can make feet blister and smell. The Society of Podiatrists advises wearing wool or silk blends of socks, although new materials such as DriMax for athletes' socks also keep sweat off the skin.

Without socks, a lot of this sweat is absorbed by the insoles or the uppers of shoes, which take 24-48 hours to dry out. Your own fungi that live on the skin of your feet will multiply merrily in a moist, dark, warm environment – perfect for athlete's foot. This fungi is called tinea pedis and you can spread it, for example, to your groin, when it is called jock itch – so not so fashionable after all.

Athlete's foot causes red, scaly, itchy, cracked skin – especially in the spaces between the toes. It can infect the nails and make them yellow, and bacteria can set up a secondary infection that can make the foot red and swollen.

Socks, because they soak up sweat, reduce the risk of athlete's foot but only if changed at least daily. Insoles or trainer liners changed every day will do the same job. If you want to go without socks you should alternate with two pairs of shoes so each can dry out.

Since servicemen often get athlete's foot, the US military has extensively studied how to prevent the condition. A study in 1944 of 2,100 servicemen training in Florida found that those given leather sandals for two months had rates of infection of only 3.5% compared with 28% in those wearing regular army footwear.

The army recommended that feet be kept clean and dry, foot baths which macerated the skin and left them open to infection should be discouraged, and socks capable of absorbing moisture were introduced where sandals were not practical (sandals are fine as keeping feet aerated is good protection from athlete's foot).

Otherwise stock up on foot deodorant and anti-fungal creams.