Locked first aid kits....
wtf?
It makes sense in some circumstances. You don't want little kids getting into the drugs after all.
No, that is why they would be mounted five feet high on the wall.
Imagine if you will, this scenario:
Bill severs his hand from his arm on a machine at the factory one day.
Tom and dike rush to his aid.
Tom begins to apply pressure to Bill's Axillary artery to slow the bleeding, while dike rushes to the nearest first aid kit to retrieve supplies to apply a tourniquet.
dike discovers the first aid kit is locked, and immediately calls for the supervisor with the key.
Bill bleeds out while waiting on the supervisor to arrive...
You don't lock first aid kits.
Drugs that may require special training to administer may be stored separately, maybe in a locked room or cabinet... but even then, the case it's self (usually called a "crash kit" or a "field surgery kit") is not locked.
Ever notice that gauze and other supplies in a first aid kit are wrapped in a tissue thin wax paper, and not mylar or plastic? It's so they can be opened easily without needing to use a knife or scissors. It kind of defeats the reasoning if you make someone have to fumble for their key to get to them.
I know, it's just a game... but still, the first time I found a locked first aid kit, I immediately thought "WTF?"...