Learn Italian: Il vapore è caldo, dunque misuriamo la temperatura. - The steam is hot, thus we measure the temperature.

Yes, absolutely! Dunque, quindi, and perciò are coordinating conjunctions that all mean "so", "therefore", or "thus". They introduce the result of a situation. You could easily say ...quindi misuriamo... or ...perciò misuriamo... here with no change in meaning. Dunque can sometimes sound a tiny bit more formal, but they are highly interchangeable.

Wait, doesn't caldo mean "cold"?

This is a classic "false friend" for English speakers! Caldo actually means "hot" or "warm" in Italian. If you want to say that something is cold, you have to use the word freddo.

Is vapore masculine or feminine, since it ends in -e?

It is masculine, which we can tell from the article il (il vapore). Nouns ending in -e can be either masculine or feminine in Italian, so it's always best to memorize them with their article. Also, notice that the adjective caldo ends in -o to match this masculine noun!

Why doesn't the sentence say noi misuriamo to show that "we" are measuring?

In Italian, the subject pronoun (noi) is usually dropped because the verb ending already makes it completely clear who is acting. The -iamo ending on misuriamo always means "we". The sentence switches from talking about "the steam" (it) to "we measure" smoothly just by changing the verb form.