The Life and Opinions of Tristram Shandy, Gentleman Book 5, Chapter 38 Summary
He says that the whole time they were in the camp they had a burning fever and a raging thirst, which protected them against moisture. Trim kept the fever going by giving them hot wine and spices, which burned out the moisture.
Yorick then turns to Trim and asks what he thinks is really going on with this heat and moisture business.