[Whether it's due to Hiro being young or it's due to Hiro just used to...being...Hiro, he's not at all bothered by their hike across the island toward the volcano and seems to be in fairly high spirits. The thing about it is that Newt is one of the people he's already decided he likes enough to compare notes with and get to know. If that means heading up to check out an active volcano, then sure.]

All the more reason it's entirely possible that's where they would put a portal. That was the idea, remember? Somewhere we wouldn't have easy access to.