When the Sun Bites Back

This is a long article; I recommend you scan it and read the sections of most interest to you rather than trying to read through it in a single sitting.

The sun is arguably the most powerful force in our daily lives. It warms the planet, drives our seasons, and has shaped human biology for hundreds of thousands of years. A little sunlight genuinely is good for you — it triggers vitamin D production and helps regulate your sleep cycle. But the same energy that sustains life can also cause real, sometimes lasting harm when you get too much. We’re not just talking about a red nose after a day at the beach. Sun injuries span a wide spectrum, from the minor annoyance of a mild sunburn to life-threatening heat stroke to decades-long processes that end in skin cancer.

Let’s walk through the main categories of sun-related injury: what they are, the biology behind them, who’s most at risk, how to prevent them, and what to do when prevention comes too late.

Before we get into specific injuries, it helps to know what we’re dealing with. The sun delivers energy to Earth in three main forms: visible light (what you see), infrared radiation (what you feel as warmth), and ultraviolet (UV) radiation, which you can neither see nor feel. UV is the primary culprit behind most sun injuries to the skin and eyes.