Oracle wrote:

Not to mention some that don't think it's needed because they took off on
a hot day. August issue of AOPA Training has a pretty good write up on
carb heat. Of course, they also address the down side of forgetting to
turn it back off too. Seems there is a large number of accidents steming
from that as well. Long story short, carb heat steals HP and yes, you
really can ice your carb on a 90+ F degree day.

http://www.ez.org/carb_ice.htm