Circuit boards (1100, 1500, 1600, 1700) and methods for fabricating circuit boards that include heaters for maintaining temperature sensitive components at an operating temperature are provided. Resistive traces (602, 702,704) are included in the circuit boards proximate temperature sensitive apparatus (1004, 1304, 1602, 1712). Thermally conductive patches (802, 902, 904) are interposed between the resistive traces and the temperature sensitive components. The thermally conductive patches establish zones of relatively uniform temperatures. According to a preferred embodiment of the invention the temperature sensitive apparatus comprises a fluid conduit (1004).