Running into fire to give emergency care to wounded comrades is something servicemen and women have done for decades.
So what happens when you put 160 NHS staff into a battlefield scenario?
The Army has taken clinical staff from the NHS to Dartmoor and has asked them to give emergency care while soldiers pretend to be the enemy and fire some blank rounds over their heads.
The NHS SW challenge is run by 243 field hospital from Okehampton camp. They've pulled all the stops out with amputee actors and fake blood.
Despite the end of Op Herrick in Afghanistan, there's still a requirement to ensure there are no gaps in staffing - the hospital still needs to be ready to deploy.
243 field hospital is the country's high readiness hospital - they're expected to be in theatre set up and providing the highest standard of care to critically ill trauma patients in just 30 days.