The introduction of new approaches for neutron detection and measurements is very rare. A similar breakthrough occurred in 1979 when Robert Apfel redefined the bubble chamber concept with his invention of the superheated drop detector. Twenty-five years after the introduction of these devices, the field of radiation detection with superheated liquids is thriving. A large variety of halocarbons are employed in the formulation of detectors, and this permits a broad range of applications. These are literally pushing the superheated emulsions to their ultimate limits and they require refinements in our understanding of the detector physics. This paper reviews the physics of superheated emulsions, the related instrumentation and their applications in radiation measurements.