A wearable device could protect soldiers from attacks from fast-acting chemical agents , by automatically injecting the antidote as soon as it’s needed.

The US Army project comprises two elements. The first is a wearable monitor that checks the user for opioid intoxication, the second is a device that automatically injects the antidote. The aim is that it will be able to distinguish between opioids and other agents, such as nerve gasses, which require different antidotes.

Previously soldiers have been issued …