カイロ

かいろ

noun

hand warmer; body warmer; heat pack

1. hand warmer; body warmer; disposable heat pack

A small packet that generates heat, used to warm the body during cold weather. Modern disposable versions contain iron powder that heats up through oxidation when exposed to air. There are also reusable types filled with lighter fluid.

カイロをポケットに入(い)れる。

I put a hand warmer in my pocket.

寒(さむ)いので、貼(は)るカイロを背中(せなか)に貼(は)った。

It was cold, so I stuck an adhesive heat pack on my back.

冬(ふゆ)の屋外(おくがい)イベントでは使(つか)い捨(す)てカイロが必需品(ひつじゅひん)だ。

Disposable hand warmers are essential at outdoor winter events.

A quintessentially Japanese winter item. The word comes from 懐炉(かいろ) (懐(ふところ) = pocket/bosom + 炉(ろ) = heater), meaning a heater kept close to the body. Usually written in katakana in modern usage.

Types

使(つか)い捨(す)てカイロ: disposable heat pack (most common type)
貼(は)るカイロ: adhesive heat pack (sticks to clothing)
充電式(じゅうでんしき)カイロ: rechargeable hand warmer

Common collocations

カイロを貼(は)る: to apply an adhesive heat pack
カイロを持(も)つ: to carry a hand warmer
カイロが温(あたた)かい: the heat pack is warm

Cultural note

Disposable カイロ are sold at every convenience store and drugstore in Japan from autumn through spring. They are commonly given as comfort items to people working outdoors and are a standard part of winter preparation.

Similar words

湯(ゆ)たんぽ: hot water bottle — used in bed for warmth
ホッカイロ: brand name (Hokkairo) often used generically for disposable heat packs

Related Words

Compare: 湯(ゆ)たんぽ (hot water bottle)

general

Added 2026.4.1 5:21 · Revised 2026.9.2 13:02

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