warm your cockles

The Japan Times Online Feb.11の記事抜粋です。
Agepizza: a deep-fried substitute for the real deal to warm your cockles in winter During the coldest stretch of winter, a warm snack helps to make the low temperatures a bit more tolerable.
文脈からすると "warm your cockles" は身体の "cockles" を暖める様に思えますが、 "cockles" は見聞きした事がありません。辞書を見ると "warm the cockles of someone's heart" と言う慣用句があることが分かりました。辞書の説明は：
　 ・McGraw-Hill Dictionary of American Idioms and Phrasal Verbs: Fig. to make someone feel warm and happy. It warms the cockles of my heart to hear you say that. Hearing that old song again warmed the cockles of her heart.
・Cambridge Idioms Dictionary: if something you see or hear warms the cockles of your heart, it makes you feel happy because it shows that people can be good and kind It's an old-fashioned romance that will warm the cockles of your heart.
Wiktionaryに語源として次のコメントがありました。
Possibly due to resemblance of cockles to hearts.
cocklesを調べると見かけは赤貝の様に見える貝ですが、私にはハートの様には見えません。