Abstract: A thermally insulated container comprising: a frusto-conical support base internally comprising a heat source with connection to an external electrical source, a flat support base, an elongated main body of circular section with thermally insulated walls with connectors arranged at the base of said body to electrically link a shielded electrical resistance; a plug with a shutter that acts as a closure of the main body mounted in the mouth of said body by means of a thread and comprising a safety pressure element. The thermally insulated container is particularly adequate for heating water to two temperature settings to be used to prepare mate beverage or to prepare other infusions. In a first embodiment the container holds 500cc of water and in another embodiment it holds one liter of water.