Because Mesona blume itself is cold, it will neutralize the cold with hot food and will not play a role in relieving summer heat. Xiancao is a cold food, so it is best to eat it with hot food to avoid offsetting the efficacy.
If people with deficiency and cold constitution want to eat Xiancao, they can take advantage of this and eat Xiancao while it is hot, without worrying about aggravating cold syndrome.