A socket for in-line circuit modules comprises: at least one row of electrical pins configured to matably engage corresponding contacts on the in-line module; and, at least two fluid connections configured to matably engage corresponding fluid connections on the in-line module, whereby fluid may be circulated into and out of the module while maintaining electrical continuity between the pins and the contacts. Alternatively, a socket for in-line circuit modules comprises: at least one row of electrical pins configured to matably engage corresponding contacts on the in-line module; and, a fluid connection configured to matably engage a corresponding fluid connection on the in-line module, whereby fluid may be introduced into the module through the socket and vented elsewhere while maintaining electrical continuity between the pins and the contacts.