Circuits on your skin telling your doctor if you've got a fever. Soldiers tracked by chips painted onto their skin. Workmen detecting harmful chemical gases thanks to a buzz from a chip on their arm.
Wearable technology isn't quite 'there' yet, but that could all change with advances in biometric tattoos.
Texas-based software company Chaotic Moon has shown off its early designs of tattoos capable of collecting health-related information and location data directly from the wearer's skin. Once collected, these stats can then by analysed by apps or sent to a relevant group, like doctors or family members.
The tattoos aren't permanent; similar to those Power Rangers stick-on transfers from your childhood, the 'tattoo stickers' apply small circuits and electronic paint directly to your skin. In addition to monitoring sweat, heart rate and hydration levels, they could support location trackers and more advanced "wearable" tech - removing the need for smartwatches or, in more extreme cases, surgical implants.
While currently a prototype, Chaotic Moon is hoping to bring a range of biometric tattoo kits to a wide market in the near future.
You can expect the "Bio tattoos hacked!" headlines to arrive shortly after. Because that's how the world seems to work these days.