As Brian says.
But dont be alarmed when your hot water stops too. This is because the tank in the roof is not filling either.
Also, find where your stoptap is just in case when the pipes thaw and should you have a burst you can turn the water off till you can call a plumber. Check under the sink unit it may be there and remember if you can turn it off before leaving the house it may prevent a flood (if it is burst) in the house if it thaws while your out.
plumbo
December 2010