Stat test confusion

[monkeymadd]

we were going through stat tests today and there is one example thats confused me

there's a group of people and every 30 mins they test their blood for alcohol levels, and also they give them a self assessment questionare every 30mins where they give a number 1-10 on confidence, urge to speak and hugging.

they used a paired t test. i don't understand because surely the info they got from the self assessment was ordinal and not interval and you need interval data to do a t test. confused