More than 200 years ago, in 1768, Lind in his monograph: „An assay on diseases incidental
to Europeans in hot climate” pointed out that habituation to hot climates reduced
the danger to health. Two centuries later, Lind and Bass in a classical study which
was carried out under hot/dry climatic conditions (49 C and 20 % rh) demonstrated
that the adaptation to heat may be described as the series of physiological adjustments
that occur when a person who is accustomed of living in a cool environment is transferred
to a hot climate. This adaptation is a process which is fully achieved after 10 to
14 days of exposure to heat, but two thirds or even 75 % of the adaptation is obtained
already within 5 days (1). According to this study improved tolerance to heat is related
to typical physiological changes: heightened sweating response, lowered heart rate,
and lowered rectal temperature during exercise in the heat.
Key words
Acclimatization - heat - cardiovascular system - sweating
