Cool air off Lake Michigan filters through as fog in downtown Chicago as temperatures climb into the 90's coupled with high humidity producing excessive heat warnings though out the Midwest, Tuesday, ... more 
Cool air off Lake Michigan filters through as fog in downtown Chicago as temperatures climb into the 90's coupled with high humidity producing excessive heat warnings though out the Midwest, Tuesday, July 19, 2011. (AP Photo/Charles Rex Arbogast) less 
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Associated Press | Photo By Charles Rex Arbogast
Tue, Jul 19, 2011 7:44 PM EDT