In general the lowering of body temperature in febrile patients via antipyretics or external methods is useless in terms of outcomes and may be harmful. Exceptions include heat stroke and other hyperthermia syndromes, stroke patients and post cardiac arrest patients.
The issue recently became more nuanced when publication of this paper from the blue journal added another possible exception: patients in septic shock treated with external cooling, in whom a decrease in pressor requirements and mortality was observed. On the other hand the use of antipyretics in septic patients across the board was associated with increased mortality in this study.
It is intuitive that external cooling would reduce pressor requirement because it induces vasoconstriction.