Dr. Sessler penned an excellent review of body temperature and the implications of hypothermia and coagulation.1  It states that body temperature averages about 37°C. In industrial nations, recently recorded data from extensive cohort studies indicate that this is closer to 36.5°C and continues to decline secondary to changes in physical activity, body composition, and antibiotic usage.2  These results included adjustments for age, height, weight, and time of day.3  This new 36.5°C value was resistant to potential confounders of ambient temperature, time of day, patient demographics, and comorbidities.2  After more than two centuries, the norm of 37°C may need replacement to a suggested new standard of 36.5°C. This new proposed normothermia standard is fluid, might continue to decline, and has patient care and quality improvement implications.

The author declares no competing interests.

1.
Sessler
DI
.
Perioperative temperature monitoring.
Anesthesiology
.
2021
;
134
:
111
8
2.
Protsiv
M
,
Ley
C
,
Lankester
J
,
Hastie
T
,
Parsonnet
J
.
Decreasing human body temperature in the United States since the industrial revolution.
Elife
.
2020
;
9
:
e49555
3.
Gurven
M
,
Kraft
TS
,
Alami
S
,
Adrian
JC
,
Linares
EC
,
Cummings
D
,
Rodriguez
DE
,
Hooper
PL
,
Jaeggi
AV
,
Gutierrez
RQ
,
Suarez
IM
,
Seabright
E
,
Kaplan
H
,
Stieglitz
J
,
Trumble
B
.
Rapidly declining body temperature in a tropical human population.
Sci Adv
.
2020
;
6
(
44
):
eabc6599