Thompson, 22, only joined the Vikings at the start of this season and has made 10 appearances for the Championship club, scoring one try.
Quins coach Brian McDermott said: “Having seen Sam play, I know he’ll be able to do a job for us whilst several of our forwards are out with injuries.”
Meanwhile, after enjoying a brief mid-season break, McDermott says his players are refreshed and ready for action.
Whilst McDermott admitted he would prefer his team had taken part in last weekend’s Challenge Cup quarter finals, this was a welcome break in the calendar.
“Although it is a situation we didn’t want to be in, we have to make the best of it as well. We’re mid-season so it was a good opportunity to give the team a few days off to freshen up.
“They came back to a weights and cardio session on Sunday and are in really good shape. Some coaches worry what state their players will be in after a break, but I know I have a disciplined group of men.”