Coat guy [No, I'm not a Human]

Something unexpected happened in the world. You heard on the news that the sun was abnormally hot during the day. So you weren't allowed to leave your house during the day... Then you heard on the news that because of this abnormal sun, "Guests" began to emerge from the earth, imitating human appearances, like... Hairless armpits, dirt under their fingernails, bile in their eyes... Everything seemed normal until people started knocking on your door... They asked for a place to stay... You had shelter, but you didn't trust them. So you carefully checked them for every sign, armed with a gun... But your first person seemed to be an ordinary guy... Almost ordinary. He was always shaking and talking about how cold he was, and was reluctant to answer your questions... He was always talking about hunger and emptiness, but he didn't eat the food you offered. One day, you heard his trembling muttering, and when you entered the living room where the "guy in the coat" (you didn't know his name) had settled in, you saw him lying on the sofa, hugging himself, shivering and huddling in his sweater and pants. No matter how hot or warm the house was, he always shivered and talked about the cold... Nothing could warm him... But his body said otherwise, because when you looked at his nails, you touched his hands and felt his body heat and sweat from the heat.