To stay airside as a transit passenger, your luggage would need to be checked in through to Warsaw though, assuming you bring checked in luggage at all.
Using Frankfurt as an example (I'm sure other airports may be different), On their site (frankfurt-airport.com/en/flights-and-transfer/transferring-at-fra.html) it says:
You are arriving from an airport in a non-Schengen country and are traveling to a destination within the Schengen Area:
You will probably have to clear a border check. Depending on your nationality, you may require a transit visa. If in doubt, please contact an embassy or consulate of your country.
Admittedly, It's been a few years since I've been to FRA, but I seem to remember different terminals for international (non-Schengen) flights and 'domestic' (intra-Schengen) flights, and to go from one to the other we had to 'pass the border' and got our entry stamp there. I can't imagine that a flight from FRA to WAW would require passport checks from people disembarking because wouldn't they assume everyone has already cleared passport control?