Abstract: A case for a mobile device, including a perimetral sidewall extending between a back face and a screen, includes a body adapted to secure the mobile device and be hand-held by a user. The body has a sidewall extending outward from a back wall to a rim. The back wall and the sidewall define the body's an inner surface and outer surface. The inner surface forms a cavity configured to receive a mobile device through an opening encircled by the rim, the inner surface configured to contact the back face and surround and contact the perimetral sidewall, securing the mobile device when the cavity receives the mobile device through the opening. The body encloses a volume in the back wall, the volume filled with a refrigerant. The body additionally encloses a volume in the sidewall, the volume of the sidewall filled with a refrigerant.