Cabling subsystem for a cryostat, comprising: - an instrument (401, 402, 417, 418, 801, 805, 1003) that comprises at least one of: a temperature sensor (401, 417, 801), a heater (402, 418, 805), a wired connector, and - a wired coupling (403, 404, 1004, 1102) to or from said instrument, characterized in that the cabling subsystem comprises: - an elongate enclosure made of a gastight material of low thermal conductivity, - at or close to both ends of said enclosure, mechanical interfaces (406, 407) for joining said enclosure to corresponding further structures (408, 409) of the cryostat in a gastight manner, - inside said enclosure, at an intermediate location between the ends of the enclosure, an internal part (410, 411, 419, 420, 802, 806) comprising material of high thermal conductivity, - outside said enclosure, at said intermediate location, an external part (412, 413, 421, 422, 803, 807) comprising material of high thermal conductivity, and - a thermally conductive connection between said internal part (410, 411, 419, 420, 802, 806) and said external part (412, 413, 421, 422, 803, 807); wherein at least one of said instrument (401, 402, 417, 418, 801, 805) and said wired coupling (403, 404, 1004, 1102) is attached to said internal part (410, 411, 419, 420, 802, 806) inside the enclosure. - an instrument (401, 402, 417, 418, 801, 805, 1003) that comprises at least one of: a temperature sensor (401, 417, 801), a heater (402, 418, 805), a wired connector, and - a wired coupling (403, 404, 1004, 1102) to or from said instrument, characterized in that the cabling subsystem comprises: - an elongate enclosure made of a gastight material of low thermal conductivity, - at or close to both ends of said enclosure, mechanical interfaces (406, 407) for joining said enclosure to corresponding further structures (408, 409) of the cryostat in a gastight manner, - inside said enclosure, at an intermediate location between the ends of the enclosure, an internal part (410, 411, 419, 420, 802, 806) comprising material of high thermal conductivity, - outside said enclosure, at said intermediate location, an external part (412, 413, 421, 422, 803, 807) comprising material of high thermal conductivity, and - a thermally conductive connection between said internal part (410, 411, 419, 420, 802, 806) and said external part (412, 413, 421, 422, 803, 807); - an elongate enclosure made of a gastight material of low thermal conductivity, - at or close to both ends of said enclosure, mechanical interfaces (406, 407) for joining said enclosure to corresponding further structures (408, 409) of the cryostat in a gastight manner, - inside said enclosure, at an intermediate location between the ends of the enclosure, an internal part (410, 411, 419, 420, 802, 806) comprising material of high thermal conductivity, - outside said enclosure, at said intermediate location, an external part (412, 413, 421, 422, 803, 807) comprising material of high thermal conductivity, and - a thermally conductive connection between said internal part (410, 411, 419, 420, 802, 806) and said external part (412, 413, 421, 422, 803, 807); wherein at least one of said instrument (401, 402, 417, 418, 801, 805) and said wired coupling (403, 404, 1004, 1102) is attached to said internal part (410, 411, 419, 420, 802, 806) inside the enclosure.