A fluid pumping apparatus comprising a pipe section (1) to contain a viscous fluid to be pumped. The pipe section (1) includes a substantially transparent window (4) impermeable by the fluid, in use, allowing microwave energy from a source to be directed into the pipe section (1) to elevate the temperature of the fluid within the pipe section (1). The apparatus preferably includes a waveguide (5) inclined with respect to a longitudinal axis of the pipe section (1) to direct microwave energy through the window (4).
