The United States resumed military attacks against targets in Iran on Tuesday. ^[1] Iran said it launched a response to the US airstrikes. ^[2] Iran issued a warning to the United States regarding an alleged strike on a wedding. ^[3] Ancient inhabitants of the territory now known as Iran developed yakhchals, large structures used to store ice and protect it from high desert temperatures, long before modern refrigeration. ^[4] The resumption of attacks occurred after approximately one month without military operations of this type between the two countries. ^[5] The United States and Iran are currently experiencing a new surge in hostilities. ^[6] The exchange of airstrikes marks the most serious escalation of the conflict between the United States and Iran in weeks. ^[7] Iran described the consequences of the alleged strike as dangerous. ^[8] Constructors used a traditional mortar called sarooj, made from a combination of sand, clay, lime, ash, goat hair, and egg whites, to provide resistance and limit heat and water entry. ^[9] Some yakhchals could reach several thousand cubic meters in capacity and feature walls up to two meters thick at the base. ^[10] The yakhchal design included a large domed structure over the storage chamber and partially subterranean ice placement to reduce exposure to external heat. ^[11] The incident has heightened tensions between Iran and the United States. ^[12]