short answer - its regional
in spain husband/wife is generally marido/mujer
in some countries the term marido implies a marriage "without benefit of clergy" - esposo meaning really married - i had read this but it was also recently explained to me recently and at length by a lady at a bus stop
It may be translate one word at a time instead of considering the whole phrase.
Instead of "to be" (you ARE hot) in Spanish they describe it has "to have" (you HAVE hot). (Yo) Tengo calor = I'm hot / I feel hot.
It's confusing, because not all "States of being" are rendered like this, for example, you say (Yo) Estoy listo BUT (yo) tengo hambre It's idiomatic, I believe.
It's idiomatic in every language, even English. Realize you aren't literally hot, you just feel like it. In Slovak, for example, we describe it with an adverb, like this: It is / It feels hot-ly to me. You can't really catch the meaning of something abstract non-idiomatically.
I'm not native Englisch and first wanted to write "My husband always is hot", but after reading it I thought that it's rather "is always", but my first idea does'nt really sound wrong for me. Is it? (I should have try and loose a heart if it is... next time if sentence occurs again)
Fareen, there are often more than one way to translate a given word. The word 'esposo' does certainly mean 'spouse' and could possibly also be translated as husband (as least in my opinion). The word 'marido' is specifically 'husband'. So it depends on which way you were translating here.
The format Duo uses to present new words is simply to throw them at you. You can always use the hover hints if you are unsure but I always advise people to avoid them as much as possible as you will learn better if you simply exercise that wonderful brain instead.
Also, I'd like to mention that Duo has a site called Tinycards where you can quiz yourself with the vocabulary. I don't believe it is completely up to date with the changes that Duo has made to the tree here but it is still very helpful in learning the vocabulary. You can find it at tinycards.duolingo.com.