Learn French: Nous avons très chaud dans cette chambre.

In French, physical feelings like being hot, cold, hungry, or thirsty are expressed using the verb avoir (to have). Instead of saying "We are hot," French speakers literally say "We have hot."

Since we "have" heat, why use très (very) instead of beaucoup (a lot)?

Even though avoir chaud acts like "having heat," you still use très to say you are very hot. Saying beaucoup chaud is incorrect in French.

Why is the word for "this" cette instead of ce?

The word chambre (bedroom) is feminine. In French, you have to match "this" to the gender of the noun. You use cette for feminine words and ce for masculine words.

Does chambre mean any room in the house?

No, chambre specifically means a bedroom. If you want to talk about a generic room in a house, you use the word pièce.