Are there any ways to protect yourself from a modern flame-thrower?

[ChristopherRPark]

If it's urban warfare and your position is in a building. But your enemies in the street have a modern flame-thrower, do you have a chance? And if mole-squads in Vietnam had had them, would US have won that war?
Update : I mean Russian Shmel' and it's likes, those that produce "vacuum"