It's physically and emotionally tough. You'd be expected to clean up mess from both floors and residents, the latter of which may not exactly grateful for your assistance. Depending on the home's policy, you might be required to cook and do kitchen duties too. As Sara says, there's a lot of shift working, and you don't get paid that much for doing it.
On the other hand, you can change people's lives, often with the smallest action, and you'll meet as many grateful residents and their families as not. Despite the downs, a lot of people do the work and wouldn't swop it for any other job in the world.