You are pushing it, Simon. Literally, I guess. This is steeping, and the water temp gradually goes down over those 3.5 minutes. Especially when it's winter, and a hot coffee is bliss. Lukewarm joe, not so much.
I prefer the variations: the Aeropress, and the even better Delter. The Delter gives a lot more control, and is my go-to travel coffee solution.