As temperatures heat up in the Fox Cities, local agencies are warning residents that heat can be dangerous and offering places to take shelter. Meanwhile, organizers are going ahead with a large Fourth of July festival as planned − but keeping an eye on the weather. An extreme heat warning is in effect until 7 p.m. June 30 for Outagamie, Waupaca, Waushara, Winnebago, Calumet, Portage, Wood, Shawano and Marathon counties.