Is it hotter in different places with the same air temperature?
While perceptions about the climate can have an effect on how we react to our environment, Guangdong and Minnesota are fundamentally different climates altogether. Using the Koppen-Geiger climate classification system, Minnesota is mostly a Temperate Continental (Dfb/Dwb) climate, meaning that is has warm summers and long cold winters, while Guangdong is a Humid Subtropical (Cfa/Cwa) climate with hot and wet summers and a short dry winter. The classification is largely based on monthly average temperatures and precipitations based on climate normals (~30-year periods).

It might be the case that temperatures match up at some points, but based on the classifications/geography of both areas, it would seem that Guangdong experiences more humidity and much longer warm periods, which combined would raise the Humidex (https://en.wikipedia.org/wiki/Humidex) above that of Minnesota.

For more information on the Koppen-Geiger classification, https://en.wikipedia.org/wiki/K%C3%B6ppen_climate_classification