Cold pressed is an anachronistic and largely unregulated label description for olive oil. Fifty years ago when most oil was made in vertical presses, the paste was pressed to make olive oil (first press) and then mixed with hot water or steam and pressed again to remove more oil. This "second pressing" was not as good; the heat had evaporated some of the delicate flavors.
Today the paste is almost always warmed to room temperature during the malaxation process before being centrifuged using horizontal decanters (Olives are harvested in the winter when it is cold). According to IOOC regulations this is still considered "cold pressed". Heating the paste excessively increases yield but degrades flavor.
Regulation 1019 of 2002 determines the use of the term "Cold Pressed" in the EU. During Malaxation and Extraction the olive paste must be kept under 27ºC (81ºF).