We have a pretty mild climate, but in July and August the temp can get up 
to the high 90s or even (gasp!) 100.  But even on such days, the nightime 
temps usually go below 70, and mid 60s is common, so they always get the 
nighttime coolness.  And our summers are not humid generally.  I pour 
water over the roots when I water the plants, but I don't make a point of 
doing it every day by any means.  
Something else that might help those in hotter climates, (especially with 
hot nights) is the fact that although they grow in full sun, they will 
also grow in quite a bit of shade with no leaf deformation, and this way 
the growing medium will not get so heated.  One person here grew them 
last year on a porch on the East side of the house; they got a little 
morning sun and shade thereafter.  They looked great.
Bob