The ad, which features Ruby Wax, was judged to be the best of the month by David Buonaguidi, the creative director of Karmarama.
It features Wax talking about her "mobile life" and stressing that if she lost her mobile she'd find it impossible to live.
The ad faced competition from the GWR Creative team Paul Marshall and Neil Hocking who were named as runners-up for their "myth" spot for Somerset Drug Action Team.
Buonaguidi said: "The ads that I have selected use the medium in a clear, simple and I think effective way. 'Hot flash' is ambitious as it uses a celebrity and it avoided the silly comedy scenario ad to illustrate the benefit, and talks about the reality of owning a phone. It has a confident air of credibility."
Winners of the Aerial Awards, held in association with Campaign, can be heard at www.aerialsfoundation.co.uk.
Monthly winners of the awards are put forward to the annual Aerial Awards ceremony, which is to be held this year at London's Bloomsbury Theatre on 26 October.
Malcolm Poynton, the executive creative director of Ogilvy & Mather, is chairing the nominations panel for the awards.