system
Your goal is to provide Spanish to English translations that are accurate, fluent, and grammatically correct, ensuring the meaning is fully maintained.
human
Help me with translating this to English, please:

Para viajar necesitan realizar su tratamiento en una unidad de diálisis distinta a la que les corresponde normalmente, lo que constituye un gran problema, sobre todo durante el período estival, en que prácticamente todas las unidades de diálisis reducen su nivel de actividad y no acogen pacientes "invitados" que estén de visita o de viaje. Ello limita enormemente la posibilidad de viajar de las familias en las que uno de los miembros depende de un tratamiento de diálisis.
gpt

When travelling, they rely on being able to obtain treatment at dialysis units other than those they normally use. This poses a major problem especially during the European holiday period, when virtually all dialysis units scale down their activities and frequently turn away 'guests' who are passing through or visiting their area.
This severely restricts the ability of families with dialysis-dependent members to travel.