Is it safe to keep stock at 160F?

Hey all,
I made chicken stock by simmering it on a stove for a few hours, and then moving it into an oven at 180F overnight (I got the temperature from a recipe). Since I put the pot in while it was simmering on the stove, I assumed that it would stay at 180F the entire night, but when I checked it in the morning, the thermometer read 160F instead, and the stock was still essentially just water. I'm planning on simmering it on the stove for a few more hours in hopes of salvaging it, but is it still safe to consume? Thanks!