The Dockworker (the fish in the bowl) has taken up residence on the Sunstone Pyramid. If you can already reach them and need what they have, use the hints for getting heat protection.

The steps only go up the left hand side of the pyramid. Perhaps this suggests they should also go up the right. (Honestly, I'm not sure if the game provides a hint about this. I discovered the solution by accident.)

Perhaps if the left and right sides of the pyramid were equally lit, you'd be able to see the steps on the right hand side. (This could be what developers were thinking, I'm not sure.)

There are no torches on the right hand side to light, so you'll have to extinguish the torches on the left.

Be sure to talk to everyone at the Settlement and check your inventory to see if you have collected something you can use to extinguish the torches.

Do you have anything in your inventory which may be water, but which has an obscure name?

You need the Hydro Air (presumably it's partly water, or a liquid) to extinguish the torches.

Have you heard the announcements about air rations being distibuted? They are being distributed in the Settlement.

Talk to the Shadowy Shopkeep, in the Settlement. He'll give you your ration of Hydro Air.

Use the Hydro Air on all the torches until the other steps are revealed.

Use the hints for getting heat protection.