You can have any combination of switches turned to the "On" position.
You have more senses than one!
Turn the first switch to the ON position. Wait 5 minutes. Turn the first switch to OFF and the second switch to ON. Open the door, go into the room. If the light is on, it is the second switch. If it is off, feel the bulb. If it is hot to the touch, it was the first switch. If it is cool to the touch, it is the third switch!