A number of hypotheses about compensatory mechanisms that allow ectothermic animals to cope with the latitudinal decrease in ambient temperature (
T
A
) have been proposed during the last century. One of these hypotheses, the ‘metabolic homeostasis’ hypothesis (MHH), states that species should show the highest thermal sensitivity of the metabolic rate (
Q
10-SMR
) at the colder end of the range of
T
A
s they usually experience in nature. This way, species should be able to minimize maintenance costs during the colder hours of the day, but quickly take advantage of increases in
T
A
during the warmer parts of the day. Here, we created a dataset that includes
Q
10-SMR
values for 58 amphibian species, assessed at four thermal ranges, to evaluate three predictions derived from the MHH. In line with this hypothesis, we found that: (i)
Q
10-SMR
values tended to be positively correlated with latitude when measured at lower
T
A
s, but negative correlated with latitude when measured at higher
T
A
s, (ii)
Q
10-SMR
measured at lower
T
A
s were higher in temperate species, whereas
Q
10-SMR
measured at higher
T
A
s were higher in tropical species, and (iii) the experimental
T
A
at which
Q
10-SMR
was maximal for each species decreased with latitude. This is the first study to our knowledge showing that the relationship between
Q
10-SMR
and latitude in ectotherms changes with the
T
A
at which
Q
10-SMR
is assessed, as predicted from an adaptive hypothesis.
This article is part of the theme issue ‘Physiological diversity, biodiversity patterns and global climate change: testing key hypotheses involving temperature and oxygen’.