The incidence of vertigo has been reported to be as high as 1.5% in the general population and some reports suggest that more than 5% of adults experience some kind of vertigo each year. In 80% of affected individuals, this symptom resulted in a medical consultation, interruption of daily activities, or sick leave.
Temperature Thresholds. According to Protabase, geraniums grow well in the temperature range of 65 to 95 degrees F during the growing season, and in the winter low temperatures between 40 to 50 degrees F, according to the A-Z Encyclopedia of Garden Plants..
The last geranium flowers of winter. I think the difference is based on the flowers. The white and red geranium still had flowers now, while the red one stopped blooming some time ago. The stress of having to survive in the cold plus showing that nice display of flowers is what made the white and red geranium more susceptible to getting sick.