A protection suit, particularly a spacesuit, has an opening in a back portion of the spacesuit for entering and exiting the suit. The spacesuit is suspended on one side of a bulkhead (5) so that a hole in the bulkhead is aligned with the opening in the back portion of the suit. The opening is closeable by a backpack (3) which fits through the hole in the bulkhead into a decontamination chamber (7) on the opposite side of the bulkhead. Two sealing and interlocking systems are used. Each system has two subsystems to provide a total of four sealing and interlocking subsystems. A first subsystem (4) connects the spacesuit to the bulkhead that separates a living and working space from an airlock. A second subsystem (6) connects a backpack to the spacesuit (1). A third subsystem (9) connects the spacesuit, preferably through the backpack (3), to a decontamination chamber (7). A fourth subsystem (12) connects the decontamination chamber to the bulkhead (5). Each subsystem (4, 6, 9, 12) is capable of hermetically sealing and interlocking the respective connection. The decontamination chamber is just large enough to accommodate the backpack.