Permanent macropores (>50 nm) had not been reported in the liquid state until a recent report by Tao Li and coworkers, describing a synthetic strategy to form a porous liquid with dual micro-macroporosity. This is prepared by producing hierarchically porous particles that are surface coated and fluidised by dispersion. Surface micropores enable permanent porosity by steric exclusion of the fluid phase. The material has a considerable water uptake capacity (27% w/w) due to large (480 nm) unoccupied macropores. This also enables switching of thermal conductivity on uptake of water. These are new properties translated from porous solids to the liquid state.