When a beer is chilled for drinking, these proteins partially precipitate forming a haze. As the beer warms up, the proteins re-dissolve.

There are two methods for getting rid of chill haze. The first is during the brewing process. Rapid chilling from after the boil to room temperature will force the Cold Break proteins to permanently precipitate and not cause Chill Haze. The second is for when you discover chill haze in an already finished beer. By chilling the beer to 1-2C forming the precipitate and then filtering through a 0.1 micron filter you can remove the haze. you will need to filter with no air exposure to ensure freshness. 

Chill haze is usually regarded as a cosmetic problem. You cannot taste it. However, chill haze indicates that there is an appreciable level of cold-break-type protein in the beer, which has been linked to long-term stability problems. Hazy beer tends to become stale sooner than non-hazy beer.