Holland have won all their World Cup games so far, but Louis Van Gaal fears the heat will benefit Mexico today.
The Round of 16 tie kicks off in Fortaleza at 17.00 UK time (16.00 GMT, 13.00 local).
“The humidity is so high it will affect the match and that is the reason we tried to get the players to be as fit as possible,” said Van Gaal in a Press conference.
“I’m quite conscious that it will also affect the Mexican team and I know they’re much more used to it than we are.”
Holland beat Chile 2-0 in the group phase and their Coach sees that as a valuable lesson for this next challenge.
“There’s not such a big difference in the way that Chile plays and Mexico plays. They play according to their quality, their skills and they’re very eager to win.
“This eagerness to win is the best part of football.”
Leroy Fer and Bruno Martins Indi are not fit enough to start “in these extreme conditions,” but could come off the bench if needed.
Van Gaal called for cooling breaks to be guaranteed in this fixture, as so far in the tournament FIFA officials have been reticent to award the time-outs.