According to one aspect of the invention, a system for controlling a temperature of a generator is provided, wherein the system includes a fluid supply in fluid communication with the generator and a heat exchange apparatus in fluid communication with the fluid supply, the generator and a cooling fluid source. The system also includes a first sensor configured to determine a first temperature of a fluid flowing from the heat exchange apparatus to the generator, a second sensor configured to determine a second temperature of the fluid flowing from the generator to the fluid supply and a controller configured to determine an operating limit temperature for the fluid based on the determined first and second temperatures.