Experiment Setup and Motivation
During the UK's record-breaking June heatwave, I tested the theory that hot coffee can cool you down better than iced coffee. The theory, from researchers at the University of Ottawa's School of Human Kinetic, suggests that hot drinks trigger sweating, which evaporates and regulates body temperature. I compared a hot double flat white and an iced oat milk latte to see which offered more relief.
Hot Coffee Test
At 9:30am, with my flat already stifling, I sipped a steaming double flat white. The scientists claim that consuming a hot drink signals the brain to increase perspiration, and the evaporative cooling effect exceeds the heat gained from the drink. However, I did not experience any sweating. Instead, the hot coffee warmed me up further, which was far from ideal. While it provided a morning energy boost, it failed to cool me down.
Iced Coffee Test
After the hot coffee, I switched to an iced version: a glass of ice, a shot of espresso, and oat milk. From the first sip, I felt more relief. The cold glass itself was beneficial, and despite testing later in the day when indoor temperatures were higher, I felt considerably cooler after the iced coffee than after the hot one.
Conclusion and Personal Preference
The hot coffee theory did not work for me. Although people in warmer European countries often prefer hot drinks to cool down, I found iced coffee far more effective and enjoyable. I will continue choosing iced drinks during the heatwave.
