Mexico study's surprising finding: Killer heat hit harder for the young than the elderly

Two theories: Outdoor workers who can't escape the heat, and young people who don't know their limits.

Both explanations make a lot of sense and are well reasoned, so it would be a sure bet they would explain at least some of the deaths if not the whole phenomenon. The culture in tropical and subtropical countries incorporate measures against extreme heat (like siesta breaks) but those measures may not be enough because of climate change or young people in particular may not be benefiting from them (since they are expected to endure harder conditions).

A good understanding of the reasons can be extremely helpful preventing deaths that are expected to increase around the globe thanks to more serious and extended heat waves. It may become necessary for people all around the globe to begin taking care in the same way as the elderly on tropical zones.

Why is this surprising?