A variable height support with a platform and a base supporting the platform and reconfigurable to selectively change a height of a support surface on the platform relative to a subjacent surface. A control assembly is operable to selectively: a) maintain the support surface at a selected height; and b) release the platform to allow the base to be reconfigured to change the height of the support surface. The control assembly has a ratchet subassembly that, with the control assembly in a first state, allows the base to be reconfigured by exerting a continuous upward force upon the platform that causes the platform to elevate and be blocked within a range at a plurality of different vertical locations against downward movement. The control assembly further has an actuator that is repositionable to change the control assembly into a second state wherein the platform can be lowered over the range.