Mobile devices and the Internet give parents a degree of flexibility that blurs the boundaries between their personal and work lives (and may lead to struggles in both domains). At the same time, adolescents are exploring their identities, doing their schoolwork, and developing and maintaining friendship through technological means. This study looked at how family members’ respective, simultaneous uses of technology affects them physiologically. It specifically examined how technology and media use affect stress (cortisol) and inflammation (interleukin IL-6) in dual earning and their parents. Adolescents with greater phone use and general media exposure and larger social networks (via Facebook) had a greater rise in their cortisol awakening response (“CAR”) and higher IL-6. When bedtime technology use, in particular, was high, greater general media use was associated with increased CAR for adolescents, but decreased CAR for fathers. Technology had no effect on mothers’ diurnal rhythms or their biosocial markers. In broad terms, weakened immune systems and higher cortisol levels suggest that technology use has potentially detrimental effects on physical and mental health in developing youth. Adolescents may be most at risk. Future research should evaluate distinctions among family members’ digital technology lives and how they affect biosocial stress markers.