Contrary to popular belief, water repeatedly boiled or left overnight does not directly cause cancer. Instead, consider the following two types of water:
1. Water that is too hot
Water that is too hot (above 50–60°C) for an extended period can severely damage the lining of the esophagus. This constant stimulation can lead to hyperplasia of the lining of the esophagus, increasing the risk of esophageal cancer. To ensure safety, wait until the water temperature drops to approximately 18–30°C before drinking.
2. Unboiled tap water
