The portable smoke blocker prevents the spread of smoke and heat in not affected areas of burning buildings. It can be fast installed into a door or entrance opening. The fire fighters can enter the room behind for their operations without the spread of smoke and heat in the building. Escape routes for the residents and retreat ways for the fire fighters stay smoke-free. It is possible for the security backup to stay close to the attacking fire fighters. The time for the rescue operation in case of a breathing protection emergency is considerable reduced. Dangerous situations through smoke and heat spread are effectively minimized or avoided.