Portals

Okay.
Assume portals, as per the video game Portal, exist and are possible, etc. etc.

If you created one portal on, say, the floor, then another one directly above, you could theoretically fall endlessly.

Given this, would a human continually falling be at terminal velocity until starvation/death from stress?

Assume the portals have been made on linoleum dining room floor and a stucco ceiling. Would it be possible for the subject to move outside the portal to stop? If so, would the impact upon landing be enough to kill them?

Impact probably would kill, unless they shut off the bottom one and shoved a mattress under before the person fell down - might be possible depending on the distance between the top and bottom portal, most normal rooms aren't that tall though.

tl;dr: death = imminent