House will handle PR during the event, from 27 November to 1 December, and for a two-month run-up period.
The event, held in association with Metro, will take place at Clapham Common for the first time this year, having previously been at Battersea Power Station.
The brief is to deliver a wide-ranging campaign appealing to a consumer and lifestyle audience with a strong local focus, as the event expands for 2013 with the aim of attracting more than 30,000 visitors in an après-ski setting.
The festival is run by brand activation specialist Vision Nine HQ, whose roster of events includes surfing and music festival Boardmasters and national action sports event NASS.
House will report to Vision Nine HQ marketing manager Mat Dixon with a remit to drive awareness of the new-look event and attendance across the five days. A core focus will be on the Saturday, when the winter sports theme is supported by a line-up of music acts.
Vision Nine HQ MD Andrew Topham said: "The event moves to a new home this year, which provides us with an opportunity to broaden the event’s appeal further into the consumer lifestyle market and attract a wider audience to Freeze. We’ve worked with House PR for the past five years and we are confident its broad consumer experience will build on previous successes, opening up the festival to a new audience."