Matching patterns of sales data for lottery games in one American county for a year against daily temperature has revealed that sales for scratch tickets (many options to select) fell by nearly $600 with every 1° Fahrenheit increase in temperature. On the other hand, sales for lotto tickets, which require fewer decisions, were not affected.
Following this finding up with a series of lab experiments, researchers found that increases of a mere 5°F in temperature (against the ‘most comfortable’ 72°) significantly reduced cognitive performance on a variety of cognitive tasks (proofreading; choosing between two cell phone plans; choosing between an innovative or a traditional product).
It is suggested that warmer temperatures, which require our body to exert cooling efforts, deplete glucose levels (interestingly, cooling ourselves down is apparently more effortful than warming ourselves up), leaving less energy available for cognition.
 . Influence of Warm Versus Cool Temperatures on Consumer Choice: A Resource Depletion Account. Journal of Marketing Research [Internet]. 2012 ;49(6):984 - 995. Available from: http://www.journals.marketingpower.com/doi/abs/10.1509/jmr.08.0205?journalCode=jmkr