The Jewish businessman Ernst Sonnenschein was registered in 1937/38 at Annagasse 3a/1/16 in Vienna's 1st district. While he managed to escape abroad in September 1938, his mother Josefine Sonnenschein (born 17 April 1885) was murdered near Maly Trostinec on 18 September 1942. All that is known of Ernst Sonnenschein is that he lived after the war in France.

On 4 August 1938, the inventory of the Technisches Museums Wien contained an entry under number 15.455 "water heater, Therme I compl." on loan from the City of Vienna, Municipal Gasworks, which was given to the museum in 2007. In 2011, the Art Restitution Advisory Board recommended that the heater, which came from Ernst Sonnenschein's apartment, be restituted to his heirs and then repurchased by the Technisches Museum Wien.