A head in the clouds in the chamber of secrets

The giant glass chamber of fog at the Hayward Gallery is predicted to attract the same kind of interest as Tate Modern's giant slides.

The fog is so effective it is impossible to see the artist Antony Gormley even when he is only feet away. He can be detected only by the "thwack" as he accidentally walks into the walls of what he calls his "cloud chamber".

"I like it a lot. I'm really thrilled," he said. "In a way, you don't know where you are. You're lost. For some people that's very frightening. For others, it's a sort of liberation."

Gallery: see more of Antony Gormley's work here

The chamber, called Blind Light, is part of the first major exhibition of Gormley's work in London. Last week he installed casts of his body on rooftops near the South Bank, all looking towards the gallery.

For Gormley, the experience of being in the chamber is a variation on his long-term practice of using his body as the basis of his work. "It's the luminous version of being moulded in plaster," he said.

He spent three months working out how to achieve the 100 per cent humidity that can create the whiteout. Oscar Wanless, one of his assistants, would not give a full explanation of how it works.

"I don't want to ruin the magic for people. It is a very dense, pure water fog. It's done electronically using cool water and humidifiers."

Wanless is right. That doesn't begin to do it justice. As I set off, coughing and spluttering as the mist catches in my throat, it is an act of faith.

You can't really get lost in a room 8.5 metres by nearly 10 metres. Can you? But it is strangely disconcerting not to be able to see as far as your own feet. Hold hands with a friend and they vanish when you take a step away.

A notice warns: "Visitors with asthma, claustrophobia or of a nervous disposition are advised to exercise caution when entering. Please do not run."

Ralph Rugoff, gallery director, said a theme runs through the exhibition, which also includes a new giant steel sculpture called Space Station and some of the artist's casts on walls and ceilings. "The show really asks people to get lost," he said.

"There are different disorientating experiences with a concrete maze in the work Allotments or lost in a mist or looking for figures that seem to appear and disappear. "People don't know what to make of much contemporary art. But I think it's a show that anyone will be able to enjoy."

He believes the chamber will have the same appeal as the recent Turbine Hall installation by Carsten Holler. "I think it will be the slides of the summer," he said. The Blind Light exhibition, sponsored by Eversheds LLP, opens on Thursday and runs until 19 August.