Symptoms of an allergic reaction which may require medical intervention include: 1  Swelling or angioedema of the face, throat, tongue, lips, eyes, hands, feet, ankles, or lower legs. 2  Hoarseness. 3  Difficulty breathing or swallowing. 4  Rash or hives. 5  Abdominal pain.
Averages for Chicago in December. December in Chicago is winter and this means an extremely cold climate that can be subject to icy winds and snow. Make sure you layer up your clothes with a warm coat over the top, as winter in Chicago can be brutal. If you're not one for cold weather, Chicago is a city to be avoided in January! Read more.
The best times to visit Chicago are April through May or September through October, when the temperatures are warm and hotel rates are reasonable. You'll also find a lot of festivals taking place in spring and fall. Summer marks Chicago's peak tourist season, with travelers from around the country hoping to take advantage of the warm weather.