Don't bring pathogens home
While our list of errands usually includes more than the grocery store, consider bringing these purchases home sooner than later and not lollygagging around town with perishables getting warmer in your trunk.
According to McEntire, bacteria can reach dangerous levels in two hours at room temperature, so while we may think it's OK to leave the groceries in the car's back seat because it's cold outside, remember that the car has been running and the sunshine will heat the interior.
While on the subject of reusable bags, let me share the results of a study from the Department of Soil, Water and Environmental Science at the University of Arizona and the school of public health at Loma Linda University.
For those who do use them, the levels of bacteria in the bags "may be a serious risk to public health as they serve as a breeding ground for dangerous foodborne bacteria".
If you try to pack everything in one bag consider placing meats on the bottom wrapped separately in a plastic bag and tied tightly closed, followed by the rest of your items on top.