The evacuation height of hotel rooms from the ground.

The "escape route map" is essential in guest room design. Many hotels and guest rooms have this label on the back of their doors. It is inconspicuous and only works at critical moments. In case of fire and other accidents, people who are familiar with it will find a way out more easily and quickly.

The gas mask is in the cupboard, so you should learn to use it. Hotels with gas masks in their rooms are generally high-end, but not everyone can find them, or they don't care how to use them.