In 1981, Unruh discovered the mathematical equivalence between quantum fields in curved spacetimes and wave fluctuations in inviscid fluids. Recently, there have been several proposals for experimental analogue gravity systems to detect the (analogue) Unruh effect: thermality due to acceleration. In this talk, I will focus on the systems using Bose-Einstein Condensates (BECs) and superfluid helium (He-II) – both of which operate at very low temperatures, often approximated as 0 K. I will present these two proposals and discuss the recently developed theory, taking the non-zero background temperature into consideration, and bringing the theory closer to realisable experiment.