A mobile device case may include a housing having a main body with a display opening, and a cap. The cap may be fixedly attachable to the main body so that when the cap is fixedly attached to the main body a housing interior is environmentally isolated from a housing exterior. The housing may further include a feedthrough connector assembly including an interior connector disposed within the housing, and an exterior connector electrically connected to the interior connector and disposed outside of the housing, the feedthrough connector assembly configured to environmentally isolate the housing interior from the housing exterior. The mobile device case may further include a selectably sealable environmental port configured to selectably allow a gas flow from the housing interior to the housing exterior, allow a gas flow from the housing exterior to the housing interior, and maintain a seal between the housing exterior and the housing interior.