热烈
rèliè · HSK 3
ardent
🔥 热 = hot + 烈 = intense/blazing; literally 'hot-blazing' = ardent
热 means hot (fire radical 灬 at the bottom). 烈 means fierce or blazing (also fire radical 灬). Together 热烈 stacks two fire-related characters to mean ardent, fervent, enthusiastic — applied to welcomes, applause, discussions.
热 — 执 zhí (phonetic) + 灬 fire radical
热 is a semantic-phonetic compound: the bottom 灬 (a variant of 火 'fire') gives the meaning of heat, while 执 on top supplies the sound. Originally written 熱, it depicted fire below a phonetic element, and the meaning naturally extended from physical heat to 'hot' weather and 'enthusiastic' feelings.