This is the 3670th most frequent Russian word.
теплые
"Тёплые" means "warm" in English.
In this sentence, 'теплые' is used to describe the pleasant, warm weather of autumn days.
Я люблю теплые дни осени.
I love warm autumn days.
Here, 'теплые' (used as a derivative form 'теплого') describes the comforting warmth of the fireplace.
Мы сидели у теплого камина вечером.
We sat by the warm fireplace in the evening.
In this context, 'теплые' metaphorically describes emotionally kind or heartfelt words.