A heat dissipating microdevice includes a board, a fluid microsystem, and a coolant. The board includes an insulator layer that has first and second surfaces, a conductor layer formed on the first surface, and a cover member disposed on the second surface. The fluid microsystem is formed in the insulator layer of the board, and includes first and second micro-channel structures, and first and second micro-conduit structures that permit fluid communication between the first and second micro-channel structures. The coolant is contained in the fluid microsystem, and flows from the second micro-channel structure to the first micro-channel structure through the first micro-conduit structure, and from the first micro-channel structure back to the second micro-channel structure through the second micro-conduit structure.