You do not have to be in a research lab, it can be a public health research or a public policy project or clinical research. Look around, e-mail people, talk to your dean and you will be able to find a mentor with a stipend. In our school (maybe yours too) there is a work study program for MS1-MS2 summer, as long as you work with a faculty member (even if it is about botany or engeneering) you will get a stipend (~3k if you stay full time for 2 months).
There are some research fellowships available, but you have to apply early.
I did AFAR summer scholarship. More info at afar.org
If you have a center at your school you should look into it. I did it at my school, but we had people from different places: NY, Puerto Rico, Ohio, etc.
PM me if you have questions about that.
This fellowship requires you to do some kind of project concerning elderly population, but if you think about it: almost any disease, public health policy has something to do with elderly population (as long as you are not doing pediatric research). And they pay you per week, check the website for the amounts....