I have seen some hot tub manufacturers quoting a study that showed that hot tubs are good for stress, depression, blood pressure, circulation and may lower blood glucose.
Having said that, i think that anyone with neuropathy or circulatory problems should be careful of the water temperature. Cold feet warming up too quickly can be painful. Anyone who has ever had chilblains will know what i mean...
Also, ever gone light headed, standing up after a hot bath?
I would say, if in doubt, check with your doc.