The English translation of the whole sentence is like this! He stared at the heat outside.

1. Heat and high temperature

2. heat, heat

3. Heat, heat and temperature

4. Hot weather, intense heat, intense heat

5. Warm, heating ———————— Heat is heating.

6. [heating] heating; Heating fee

Next to the heating, I think it means next to the heating.

So I think the whole sentence should be that he is looking out by the radiator.

I hope I can help you.