General Brazilian
esfriar, se acalmar, arrefecer
Most common usage in Brazilian Portuguese
Rio de Janeiro
se acalmar, desanimar
Often used to indicate both temperature and emotional cooling
São Paulo
esfriar, se tranquilizar
Formal and informal contexts
Portugal
arrefecer, acalmar-se, desanimar
Arrefecer more common for temperature; acalmar-se for emotions