Boiling water will not melt a cooler but the boiling water can soften or even warp the plastic of the cooler, especially with cheaper coolers.
The heat from the boiling water may also damage the coolers insulation and compromise the cooler's ability to keep things cold.
some coolers can handle boiling water and other boiling liquids better than others but it's best to avoid putting boiling water or other boiling liquids in a cooler if it's plastic.
Igloo coolers can be used keep drinks hot but boiling hot liquids should not be used in the Igloo cooler.
To use your Igloo cooler to keep your drinks hot you should preheat the Igloo cooler with some hot water first.
Igloo coolers are mainly designed to keep beverages cold but they can also keep beverages and drinks hot and are effective at maintaining the temperature of hot liquids.
Igloo coolers are insulated and so they are effective at insulating both hot and cold liquids and makes them suitable for keeping hot liquids warm for a period of time.
Even some other Igloo models such as the Yukon lines and Sportsman which are dry ice compatible can also be used with hot liquids and hot drinks.
The Igloo 5 gallon seat top cooler is also designed to keep hot beverages hot although it's also crucial to be cautious when dispensing hot liquids and hot drinks to avoid burns.
Some Igloo coolers can be used safely for hot liquids although other types of Igloo coolers such as the 10 gallon orange cooler is not designed for hot liquids and is made for cold liquids but can be used for hot liquids but it could possibly damage it and cause it to warp or crack the inner liner.
Pre-warm the Igloo cooler with hot water before adding hot liquids or hot drinks to the Igloo cooler to maximize the retention of the heat.