I'm not sure which is worse.
Thankfully I've never experienced either one.
But if you've ever been inside those trams, with no air-conditioning, sharing about a 5 x 5 foot space with 4 others, and having to slump down a bit to avoid hitting your head on the top of the car, then I'd say the first choice would be a little worse.
A tram car.
But then again, I hate heights, especially with no net below.
There is only one way to ascertain the answer to this question. Let's put all the dudes and ladies who were trapped for two hours up ON (not in) the top for two more hours. Then we'll ask THEM what is worse.
You know, use science to figure out the answer. It's the only way.