It’s not seance as you can think 😁 This is as known UV lamp “light baths”. The use of quartz lamps was introduced in the USSR in the 1950s.
In the Soviet Union, their introduction became so widespread that the irradiation of children with quartz lamps as the prevention of rickets was introduced in every kindergarten. It were given to Soviet kids in an attempt to supply them with vitamin D during the winter.
Quartz lamp “light baths” was a must before bedtime in kindergarten. It was also said that Soviet children were also fed fish oil to get vitamin D.