I also went on the hiking tour where we hiked around 4 hours on the lava fields. My zoom camera was able to pick up the lava going directly into the ocean. This was cool, but then our guide took us on up the mountain more and we watched for steam, hoping it would lead us to a broken open lava tube. It did, and we were, amazingly enough, able to see the lava flowing right under our feet (about 3 to 4 feet down). It was amazing, but I agree with you. You must be able to do a strenous hike and endure the extreme heat. It is not for the physically inactive. Enjoy!!