Mammoth Ranger 65 Quart Premium Large Hard Sided Cooler with 8+ Days Ice Retention, White

Mammoth Coolers are the finest rotational molded (roto-mold) coolers available anywhere. They are injected with premium insulation which keeps items in the cooler cold and makes ice last longer. The coolers come with a lifetime guarantee. Different variables affect the length of how long a cooler can retain ice such as the outside temperature and humidity which will vary everywhere. Another big factor is how often you open the cooler. When you open a cooler it has to cool down the inside of the cooler to match the temperature of the ice and water. Another factor is the type of ice that you use in the cooler (crushed, cubed, block, dry). In order to maximize the cold retention ability of your Mammoth, we recommend that you keep your Mammoth in a cool place before use (even a frozen environment is ok), or pre-chill it with ice or dry ice.  The goal is to decrease the internal temperature of the cooler prior to adding your contents.  The colder the inside walls of the cooler, the better.   Starting off with a pre-chilled cooler will greatly help to extend the life of your ice.  Believe it or not, some Mammoth users creatively use their Mammoth to maintain food warmth during a Bar-B-Q sessions or a tailgate party!  In this case, pre-heating will give similar, positive results. The colder the contents are going in, the longer they will stay cool.  Chilling or freezing the contents before they go into the Mammoth will bring much longer ice retention. Ice temperature can vary greatly depending on the source and type of ice.  Water becomes ice at 32°F, but ice can get much colder.   Block ice is typically the coldest type of ice that is readily available. We recommend using multiple types of ice for best results. Cover the bottom of the Mammoth with block ice, then pack the contents onto the blocks, and cover with cubed ice to fill empty spaces. Air will make your ice melt quickly. In order to keep air to minimum inside the Mammoth, we recommend that you fill it with as much contents or ice as possible. Large areas of air will cause ice to melt faster.   Cold water is a solution to displace air, if your situation allows for that. Mammoth Coolers are installed with a rubber gasket seal on the lid.  The main purpose is to keep outside air out. (See #4 above)  This seal is only beneficial when the lid is completely and securely latched down.  Furthermore, frequent openings of the lid will decrease ice retention.