International Agency for Research on Cancer - have shown that drinking very hot beverages can directly impact your health. For instance, there is an increased relative risk for esophageal cancer, directly related to temperature. According to those studies, the ideal temperature is 65ºC (149ºF) or less.
Very hot water will produce a very strong and bitter mate at the beginning - even with a slightly burnt flavor - and then it will quickly lose its flavor. Because mate is drunk through long periods of time, it is important that it has a consistent performance.