Nomadic tribesmen in the desert of the southeastern Moroccan region of Merzouga are offering wellness treatments to tourists by digging holes in 150m (492ft) high sand dunes for visitors to bury themselves neck-deep in the heated ground for ten minute sessions.

Said to have the same effect as a sauna, tourists pay up to €10 (US$13, £8) to be trapped in the sand – a therapy that is supposed to relieve symptoms of rheumatism, lumbago, polyarthritis and some skin disorders.

After ten minutes, the ‘guests’ are wrapped in hot towels by members of the Berber Ait Atta tribe to avoid shock that can occur from the body cooling too quickly.

Using hot sand to treat rheumatic orthopedic conditions is not unheard of. The spa at the Porto Santo Hotel in Porto Santo, Portugal, has sand beds, featuring local sand that is heated to 40-43°C (104-109°F). Twice a day, guests spend 30 minutes in the sand – which is a mix of coral reefs, seashells and volcanic ash. Scientists from the University of Oslo, Norway, and the University of Aveiro, Portugal have already proved that the sands in Porto Santo have a high content of calcium and strontium – helpful in the relief of rheumatism.

The number of heated sand-related products on the spa market have also increased over the past few years. In 2012, spa equipment manufacturer Gharieni developed the MLX Quartz wellness couch filled with alpha-quartz sand which is then heated to the desired temperature.

Lemi, manufacturer of spa and beauty equipment, unveiled a spa cabin in July this year that features a bed of spherical yellow quartz that are said to have a therapeutic effect.

Most recently, bath and wellness system supplier Trautwein created the new ‘Vulkanosand’ table in September, which allows guests to lie on a waterproof foil that sits over lava sand obtained from volcanic rock which warms up and heats the body.