If the health of one of the characters drops to zero, this character is no longer available for the game until you return to the Base.

After evacuation to the Base, the character is restored with an incomplete number of health points.

If the health of all the characters available for the player drops to 0, the game will evacuate all of them to the Base with an incomplete number of health points.

After the evacuation, everything that was in the backpack will be lost.  Only what was in the pockets of the characters will be saved.  You can try to return to the evacuation point and collect your belongings.

Evacuation point with the items from the backpack is showed with a special icon on the map.

You have the option to save your loot from the backpack by using C-coins or by watching an ad before evacuation.