I have heard that all hotels in this part of italy perhaps other parts too are thermal pools therefore unsafe for pregnant women and children under 12 to use for more than 5-10 minutes at any one time does anyone know the reason for this - is it because of high mineral content - also surely pools are cool and not thermall heated in summertime

Thermally heated pools are where the water flows into the pool at the temperature it reaches the surface of the earth. Often thermally heated pools are linked to an area of volcanic activity (usually dormant or even supposedly-extinct) like around Etna, Vesuvius and the Black Forest.

The pool will be at the same temperature all year round, winter and summer, with not 'human' intervention.

I enjoy the local thermal baths (near Freiburg) but would advise spending only 20 mins max in them at a time. Then get out and have a rest! Why? Well the mineral composition of the water is different and you usually feel more buoyant. When you get out, gravity takes over with a vengeance, and you feel that all points of you are going south with ever increasing speed!! You many also find that these minerals 'attack' your spectacles.

Used wisely a thermal bath can be a wonderful experience - do take advice if offered by the establishment concerned!