Slide heater

In a slide heater for use in a slide processing apparatus in which slides are treated with fluids and heated substantially uniformly across the slide's surface via a thermal conduction transfer interface surface between an upper surface of the slide heater and a slide carried thereon, the improvement wherein said upper surface of the slide heater has a plurality of slots or channels formed therein running to an edge thereof, wherein the slots or channels occupy up to about 50% of the upper surface area of said heater, and have a depth-to-width ratio of about 0.2 to 2, said slots or channels being open at least one end thereof whereby to permit venting of bubbles formed by boiling of fluid as may be trapped between the slide heater and a slide carried thereon without lifting or dislocating the slide.