Brits don't think you can appreciate the flavor of a beer if it is icy cold so they drink beer at cellar temperature. It's not warm, but it's not very chilled either. Ask the bar staff about local craft beers.
Davis says that originally, ales as an entire category were served warmer because they were fermented at warmer temperatures in order to get the yeasts to activate. Then, as German brewers started using lager yeast, which is fermented at cooler temperatures, the perception of the ideal serving temperature shifted.
All beers should be served between 38-55° F. Darker beers are served warmer than lighter beers. Macro lagers are served as cold as the Rockies. Serve beers a few degrees colder than the target temperature, to accommodate for warming from the glass and the drinker's hands.