[י"ז סיון תשי"ג]
...רופא דתי - בטח יוכל לסדר שלא יוזקק לרחץ בש"ק. ושבת עצמה מרפאת וכל' רז"ל שבת היא מלזעוק (ובכ"ז ועי"ז) רפואה קרובה לבוא...
17 Sivan 5713.
...A religious doctor can surely arrange matters so that bathing will not be necessary on Shabbos. And Shabbos itself brings healing, as our Sages say: 'Shabbos is for refraining from crying out' (and through this, healing is close to coming)...
Summary
The Rebbe teaches that with proper planning, one can avoid needing to bathe for medical reasons on Shabbos, and emphasizes the inherent healing power of Shabbos itself.