Conventional mechanistic models for the incipience of boiling exist for near wall temperature and velocity profiles appropriate to turbulent flow. These models are revisited for fully developed laminar flow between parallel plates. The evaluation is focused on channels of width ranging from 0.000001 meters to 0.001 meters. The results show that the heat flux required for incipience of boiling is inversely proportional to the channel width. This analysis further indicates that the applied flux required for incipience of boiling can be quite high even for saturated bulk flow conditions in small channels. This allows significant bulk superheat to develop prior to incipience of boiling in flow situations where the heat flux is low. A simple closed form expression is developed that describes the conditions required for incipience of boiling prior to the bulk fluid reaching saturated conditions.