Yeah! A cold spell means the planet can't be getting warmer!
How often must this same silly argument be trotted out? I could point out record hot temperatures recorded in 2018 in various places. The question isn't whether any one place was exceptionally hot or cold at any one time, but whether the temperature of the planet is growing warmer or not (and how much humanity affects global temperature change, of course).
A record cold temperature in Chicago is only important if it can be shown as part of an overall trend, at least in the context of the global warming argument.
To be clear, I'm not arguing for the idea of man-made global warming, I'm arguing against your argument that the temperature in Chicago is any sort of reliable indication of the temperature trend of the planet.