A good question. I have been wondering about it myself. Since people
thought that they should drink spirits in hot weather in order to "warm up"
their insides which they believed had been left weak and cold by sweating,
and since little beer was brewed in the early colonial South (weak beer of
less than 4 per cent alcohol by volume, as was traditionally drunk in
northern Europe, would have rehydrated rather than dehydrated), it would be
logical to assume that a lot of people must have died as a result (directly
or indirectly) of dehydration. Definitely a subject deserving of research.
Presumably you have read K. O. Kupperman, "Fear of Hot Climates in the
Anglo-American Colonial Experience," William and Mary Quarterly, 3rd
Series, Vol. 41 (1984) pp. 213-40. Another useful original source, if you
can find it, is Richard Ligon (or Lygon), "A True and Exact History of the
Island of Barbadoes" (London, 1673). There is a copy in the British Library
but I don't know about the US.