Related Clues:

• "Wait a minute!"
• Stop right there
• Turn to ice
• Render very cold
• Change to ice
• Hold at fixed level - say prices
• Cease action - get a grip!
• Harden into ice
• Informally, cease action
• Turn into ice
• It's to make it hard that one lets it go up on the wall
• This will make it hard to have this high on hte wall by the sound of it
• What you'd never do in 29 across is sound like 30 across
• Lets out the sound of it, however hard it gets
• It's hard to get so cold as to sound as if one was in the building