The introduction of rapid diagnostic tests (RDTs) has the potential to provide a way of more accurately directing ACTs to those that need them and may also encourage clinicians to consider alternative diagnoses in test-negative cases, reducing the risk of missing treatable, and potentially fatal, alternative causes of febrile illness. RDTs to direct ACT use also have the possibility to be cost-effective, but only if clinicians prescribe logically on the basis of test results.