A prosthetic socket liner. A liner of the prosthetic socket liner has an inner and outer surface, the inner surface configured to engage skin of a user's residual limb and the outer surface configured to engage a surface of a socket of a prosthesis. An air channel coupled to the liner and to a valve extends downwardly towards a closed end of the liner and is configured to transfer air between an outer surface of the liner and ambient air through the valve. In implementations the air channel is configured to channel air between an inside of a cavity and a location outside the cavity. A method of donning a socket of a prosthesis includes donning a liner of a prosthetic socket liner over a residual limb, opening a valve on the liner, inserting the liner into a socket of a prosthesis with the valve open, and closing the valve.
