We should note that all of these places of thermal extremes (Finnish saunas, Japanese hot baths, American beaches and mountains) have their opposites close at hand. There are possibly two reasons for having the extremes right next to each other.
The first is physiological: the availability of extremes ensures that we can move from one to the other to maintain a thermal balance.
The second might be termed aesthetic: the experience of each extreme is made more acute by contrast to the other.
Works of art which have great life often have intense contrast within: rough/smooth, solid/void, loud/silent, empty/full. It is the difference between opposites which gives birth to something. Contrast is what often gives other principles their degree of life – the intensity of the boundary, the markedness of the alternating repetition.
Contrast strengthens centers by making each a deeper entity of itself, and thereby giving deeper meaning to both. It is, at its simplest, what allows us to differentiate. But meaningless contrast remains meaningless. It is only when centers are actively, mutually, and meaningfully composed that it acts to deepen the whole.
Thy Godlike crime was to be kind,
To render with thy precepts less
The sum of human wretchedness,
And strengthen Man with his own mind;
But baffled as thou wert from high,
Still in thy patient energy,
In the endurance, and repulse
Of thine impenetrable Spirit,
Which Earth and Heaven could not convulse,
A mighty lesson we inherit.
Like thee, Man is in part divine,
A troubled stream from a pure source;
And Man in portions can foresee
His own funereal destiny;
His wretchedness, and his resistance,
And his sad unallied existence:
To which his Spirit may oppose
Itself—and equal to all woes,
And a firm will, and a deep sense,
Which even in torture can descry
Its own concenter'd recompense,
Triumphant where it dares defy,
And making Death a Victory.