A cooler carton for items such as beverage containers is erected from a blank (11) having a unique configuration of panels (12, 13, 14, 16, 17, 41, 47, 56, 66, 96, 99), tabs (28, 29, 31, 32), flaps (111), creases (18, 19, 21, 22, 33, 34, 36, 37, 42, 48, 57, 67, 77, 87), perforations (23, 26, 27), cut-creases (24, 97, 101), and gussets (46, 52, 81, 91). The erected carton has top panels (12, 17) forming a top with a central longitudinal perforation line (23, 26) and oblique cut-creases and perforation lines (24, 27) extending from the ends of the central perforation line (23, 26) to the corners of the top. Flaps (111) are formed at respective end portions of the top by folded tabs (28, 29, 31, 32). In use, the carton is erected and filled with articles to be contained. An end user may open the carton by pulling up and back on the flaps (111) at the end portions of the top, which severs the oblique cut-creases and perforation lines (23, 26), and severs the top along its central perforation line (23, 26). As a result, the top opens up and forms a containment skirt that extends above the level of beverage containers in the carton. Ice can then be added atop the containers to cool their contents and the ice is contained by the skirt. Gussets (46, 52, 81, 91) are formed at the lower corner portions of the carton, which, along with a moisture barrier, prevent accumulated water from melting ice from leaking from the bottom region of the carton.