Several parts combine into one character.

寒 packs an entire winter scene into one character. The compound ideograph contains four elements stacked together: 宀 (a roof / house) on top, 茻 (grass or straw) in the middle, 人 (a person) curled within, and 冫 (ice) at the bottom. The literal picture is precisely what cold meant to ancient Chinese people: a person inside a house, with straw piled around for insulation, and ice formed at their feet — the desperate winter posture of someone trying to stay warm against the elements. Few characters preserve such a complete narrative scene. The oracle bone form makes this even more vivid, with each element clearly visible.

Korean reading "han." 寒冷 (hallaeng, cold climate), 寒波 (hanpa, cold wave — used in winter weather forecasts), 惡寒 (ohan, "evil cold" = chills / shivers from fever), 寒氣 (hangi, cold air / chills), 寒帶 (handae, frigid zone), 大寒 / 小寒 (daehan, sohan — "Great Cold" and "Small Cold," two of the 24 traditional solar terms in the Korean lunar calendar marking the coldest days of January). Korean students learn the 24 solar terms in school, and 寒 appears prominently in winter ones.

Mandarin hán, 2nd tone. 寒 (hán, cold), 寒冷 (hánlěng, cold), 寒假 (hánjià, "cold vacation" = winter break — note Mandarin's elegant compound: a vacation taken because of the cold), 寒带 (hándài, frigid zone), 寒流 (hánliú, cold current / cold front). The Mandarin 寒假 is more etymologically transparent than the Japanese equivalent 冬休み (fuyuyasumi, "winter rest").

Japanese on-reading カン (kan) — 寒冷 (kanrei, cold climate), 寒波 (kanpa, cold wave), 寒帯 (kantai, frigid zone), 大寒 (daikan, "great cold" — same solar-term tradition as Korea, observed in Japanese culture). Kun-reading さむい (samui, "cold") — 寒い (samui) is one of the very first adjectives Japanese learners memorize. Critical homophone caveat: さむい (寒い) describes weather / ambient cold, while つめたい (冷たい, written with a different kanji) describes objects that are cold to the touch (cold water, cold metal). Saying 水が寒い ("the water is samui") sounds odd; you say 水が冷たい ("the water is tsumetai"). The split between ambient cold (寒) and tactile cold (冷) is one of the foundational temperature distinctions in Japanese.

Memory aid: a roof (宀) sheltering a person (人) packed in straw with ice (冫) below — the complete winter scene compressed into a single character.