An environmentally friendly and inexpensive dielectric coolant for fuel cell stacks. The present invention is directed to a fuel cell (1), a system, and a method of cooling a fuel cell (16). The fuel cell is configured to react fuel with oxygen (52) to generate an electric current and at least one reaction product and comprises an electrochemical catalytic reaction cell (1) configured to include a fuel flowpath (26), an oxygen flowpath (58), and a coolant flowpath (16) fluidly decoupled from the fuel flowpath and the oxygen flowpath. The coolant flowpath defines a coolant isolation manifold (20) that includes a fluid dielectric coolant comprising a vegetable oil-based dielectric fluid.