Group 1 - The article discusses the preference of the stomach for cooler temperatures, suggesting that drinking warm water can damage the gastric mucosal barrier, potentially leading to gastritis and other serious conditions [2] - It highlights that while cold water can stimulate the gastrointestinal tract, it is generally safe for most people as the body regulates temperature effectively [3][4] - The article emphasizes the importance of hygiene when consuming ice water, noting that industrially produced ice is usually safe, but contamination can still occur [3] Group 2 - Recommendations are made for consuming ice water, suggesting that adults should limit intake to 500 milliliters at a time and allow several hours between large quantities to avoid gastrointestinal discomfort [6] - It identifies five specific groups of individuals who should avoid ice water due to their sensitive gastrointestinal systems, including those with acute gastritis and children with underdeveloped digestive systems [7][9] - The article provides guidance on preferred beverages during hot weather, recommending plain ice water and cold brew tea while advising against sugary drinks [8]