> Maybe it hurts less, but you're still doing damage to your skin.

I think this is where we're both getting dumbfounded. (or maybe just me!)

My conception of a "sunburn" is more about the symptoms than the underlying damage. Since you seem to be thinking in terms of damage as well, perhaps regardless of actual symptoms, yes, the sun still damages skin regardless. I wholeheartedly agree.

Though we might not be on the same page about the level of damage or what that even means.

> The mechanism of a sunburn is like touching a hot pan, not an allergic reaction or a bruise.

No, a sunburn and a heat burn is not equivalent.

An aspirin might alleviate sunburn symptoms because everything from the redness to the pain to the peeling are biological responses. It's meant to both be protective and to kill or remove cells that have had their DNA or RNA damaged. That's the level at which the damage is occurring. Without the inflammatory response, it's unlikely you'd even know you were damaged by the sun at all. Well, in the immediate sense. Lingering damage can certainly become cancer down the road.

Aspirin won't prevent harm from touching a hotplate because most of the symptoms are caused directly by the thermal energy itself. In that case, you're transferring enough energy into the skin that it's denaturing and even combusting. The pain is not just from any inflammation but from nerve endings being affected.

In principle, UV is capable of doing the same, but that's simply not the level of power we're dealing with from sunlight. You might know that it's possible to cook food using the sun's rays, but if we cut out the rest of the light spectrum except for UV, that food won't ever cook.

To summarize: Sunburns are from UV damage to DNA, and hotplate burns are from thermal damage to tissue.

> Why would you think there's a connection there?

Because in such a case you're adding inflammation on top of more inflammation. A chronic level of inflammation means the body is already in a more sensitive state. This can aggravate acute forms of damage because the inflammatory response is already heightened.

Inflammation also is not necessarily in proportion to the damage being done. The inflammatory responses are important for survival, but more inflammation isn't necessarily better. If a healthy person who's not in a pro-inflammatory state doesn't suffer sunburns as easily as others, there's no reason to believe that there's some sort of malfunction or that it's any more dangerous. But getting burned easily by the sun is not only worse from a practical standpoint but, in my hypothesis, might be a result of over-sensitivity.

By no means am I saying that I actually know that's what's going on with sunburns in particular, but hopefully you can understand where I'm coming from.

And good luck ever having this studied in humans or animals. Such experiments wouldn't be allowed for ethical reasons, and pharmaceutical companies would have no incentive in funding such research.

To try and hit the point home, I have secondhand experience with incongruent inflammation.

One of my good friends has a condition called CRPS, or Complex Regional Pain Syndrome. It's ultimately an inflammatory response gone haywire, so much so that it is more painful than childbirth if left untreated.

If you have the stomach for looking at photos of medical conditions, look up CRPS on Wikipedia. There's photo in the article of a severe case, and you'll notice it looks uncannily like a bad sunburn.