Мерзлоты literally translates to "permafrost" or "frozen ground". It's a striking and somewhat unusual word to find in a pop song, making it memorable.
In the context of the song, the singer uses it metaphorically to describe a deep, emotional coldness or numbness within himself, asking his beloved to warm him "От той душевной мерзлоты" (from that spiritual permafrost). This poetic usage adds a unique depth to the lyrics.
Yurii Shatunov's "И Шли Дожди" (I Shli Dozhdi) plunges us into a world where the weather perfectly mirrors inner turmoil. The sky "стонало небо" [moaned] and the rain just kept pouring, but our singer wasn't happy. Instead, he found solace in his ability to love, even as the world around him felt cold and bleak. He's longing for someone to warm him "От той душевной мерзлоты" [from that spiritual permafrost], a powerful image for deep emotional chill.
He's literally wading through the mud, "вязну в слякоти сырой" [I'm stuck in the wet slush], following the shadow of the person he loves, feeling both with them and not with them. It's a tough path, but he chose it himself and has no regrets. He stumbles, gets back up, and keeps going, even if he's "в этих я дождях тону" [drowning in these rains]. It's a really honest look at enduring love through hardship, where the rain isn't just rain, but a symbol of all the difficulties he's facing.