"Heat of the battle" is an idiom to express the most intense and fierce fighting. AT: "to where the battle was most intense" (See: [[rc://en/ta/man/translate/figs-idiom]])
This is an idiom to represent being very busy and preoccupied. AT: "doing other things" or "doing this and that" (See: [[rc://en/ta/man/translate/figs-idiom]])