Each year, 160 U.S. homes experience Christmas tree fires. They are hot, fast, dangerous — and preventable. In this video, the ACS Reactions team tests different Christmas tree watering conditions, including an internet recipe that supposedly fireproofs your Christmas tree with borax, to investigate the science behind preventing these fires. With some help from the University of Maryland, they light some Christmas trees on fire and conclude that just plain water is one of the best things you can give your tree to keep your home safe.

Wearing sunscreen is important to protect your skin from the harmful effects of UV radiation but doesn’t cool people off. However, a new formula, described in ACS’ Nano Letters, protects against both UV light and heat from the sun using radiative cooling. The prototype sunblock kept human skin up to 11 degrees Fahrenheit (6 degrees Celsius) cooler than bare skin, or around 6 F (3 C) cooler than existing sunscreens.

Mexican Coke tastes different than American Coke; after all, it’s sweetened using cane sugar instead of high-fructose corn syrup. That, at least, was the conventional wisdom until 2011, when a paper published in the journal Obesity found that Mexican Coke contained no cane sugar. Instead, the authors found plenty of glucose and fructose, which are the main ingredients in high-fructose corn syrup. Join our Reactions host George as he tests a bottle of Mexican Coke and confirms — to his utter surprise — the presence of glucose, then follows this mystery step by step to its shocking conclusion.