Barricade yourself inside
Definition 1 of 1
Pro Tip 1/3Emergency Use
The phrase often implies a reaction to immediate danger or to keep something threatening out. 
As the floodwaters rose, we barricaded ourselves inside the cabin.
Pro Tip 2/3Physical Blockade
Use physical objects like furniture to create a barrier, not just locking doors. 
The students barricaded themselves inside the classroom using desks and chairs.
Pro Tip 3/3Temporary Safety
The action is a temporary solution to feel safe, not a permanent fix. 
During the riot, they barricaded themselves inside until help arrived.