"The story delivers a desired call to drink that soft drink that people tend to drink when the weather is too hot."
It all depends on what he means.
"That..." is what's known as a restrictive clause, because the information following the "that" restricts the meaning of the word modified in a manner essential to the meaning of the sentence.
"Which..." is what's known as an unrestrictive clause, because the information following the "which" provides extra information rather than limiting the meaning of the word modified.
So, If Orlando was referring to a specific soft drink that people tend to drink when the weather is too hot, "that" is correct. However, if Orlando meant that people tend to drink soft drinks in general when it's too hot, he should have written:
"a call to drink that soft drink, which people tend to do when the weather is too hot."
Note the comma before "which" -- in general, you will only use "which" clauses after a comma. If you don't need a comma, you probably want "that." If you do need a comma, you probably want "which"