The present invention refers to a seat cushion assembly (10), in particular for a personal mobility vehicle, comprising: a flexible envelope； and a thixotropic fluid contained within the flexible polymer envelope, the thixotropic fluid including a base fluid comprising an oil and a block polymer, the block polymer having a first portion that has an affinity to the oil and a second portion, the first and second portions interacting to provide a fluid viscosity that deforms under a generally constantly applied pressure and retains the deformed shape when the pressure is removed, the thixotropic fluid having concentration of nanoparticles configured to increase heat transfer from a seated user to provide a reduced temperature sensory effect. It also refers to a personal mobility vehicle, in particular in form of a wheelchair, having such a seat cushion assembly (10).
