Autumn still feels a long way away in the ancient baths of Terme di Saturnia in early October. Italian families, and visitors from further afield, lounge in the thermal waters that pour from the ground at a rate of 800 litres per second, and at a constant temperature of 37.5C.

The spa, about 70 miles south of Siena, has a long-held reputation as a place where precious natural materials are used in the pursuit of beauty and wellness – the Etruscans and, after them, the ancient Romans sought out these natural baths for their health-giving waters. But this month, this Tuscan resort has added a new line in pampering: a treatment in which the entire body is covered with 24-carat gold.

The jury is out on the benefits of gold for the skin. Beauty companies cite its anti-ageing, hydrating and nourishing qualities, which improve skin elasticity and generally give it a glow. Some in the medical community disagree and say its benefits are not proven, and that gold may even be an allergen to people with sensitive skins.