Chill haze is caused by hop polyphenols and barley proteins combining to form complexes at lower temperatures resulting in colloidal particles in the beer which break up again at higher temperatures. There are a variety of approaches aimed at reducing susceptibility to chill haze which, generally, involve removing one or both of the components or removing the particles once formed. Methods include: a vigorous boil to coagulate protein (hot break), rapid wort cooling to do likewise (cold break), kettle finings (e.g. Irish moss), beer finings (e.g. isinglass, gelatin, which are both forms of collagen, PVPP), prolonged cold conditioning (lagering), enzyme additions (e.g. Brewer’ Clarex). I find heavily hopped/dry-hopped beers seem particularly prone.
It will clear again if you keep it cold, the colder the better. It will take a while though,.
