This is an undergarment for cooling the Orlan D space suit, used in 1979 by Valery Rjumin (Валерий Рюмин), who entered space on the space station Salyut-6 during a 175-day orbital flight. It is a unique case in history where the suit was actually brought back from space to check the condition of the wires and for additional testing. The undergarment can be used with spacesuits equipped with both manual and automatic thermal control systems. It is a meshy garment made of a knitted, net-like fabric through which elastic pipes of a cooling system are woven. The garment fits tightly to the body, pressing the pipes of the cooling system close to the cosmonaut’s body. The mesh structure of the fabric facilitates the access of ventilating air to the surface of the human body. The suit can be used with spacesuits featuring both manual and automatic thermal control systems. The principles of operation and its basic design solutions are the same as in the earlier version of the suit and are made individually for each cosmonaut.