A fridge would be too cold. I have read some people have wine fridges & they work great for PW. Not sure about HW. I keep mine in our basement, which is the coolest place in our house.
Also, after re-reading my post .... Pw do need to be eaten fast, or they turn black & get ready to change .... But you do have roughly 3 weeks. However, HW can grow much faster. Like a couple days fr little to big.
Hope that helps.