solution is easy:
replace
mask = (50 < df['heart rate'] < 101 &
140 < df['systolic blood pressure'] < 160 &
90 < df['dyastolic blood pressure'] < 100 &
35 < df['temperature'] < 39 &
11 < df['respiratory rate'] < 19 &
95 < df['pulse oximetry'] < 100
, "excellent", "critical")
by
mask = ((50 < df['heart rate'] < 101) &
(140 < df['systolic blood pressure'] < 160) &
(90 < df['dyastolic blood pressure'] < 100) &
(35 < df['temperature'] < 39) &
(11 < df['respiratory rate'] < 19) &
(95 < df['pulse oximetry'] < 100)
, "excellent", "critical")