Medea's Sunscreen

Medea's Sunscreen is a brand of sunscreen used by demigods. It is presumably only for magical uses. It's only named variants are SPF 50,000 and SPF 5,000. In the myths, Medea, the sorceress, gave this to Jason (Argonaut), though it wasn't known as "sunscreen" then (it was called magical lotion). According to Annabeth, she has the Tropical Coconut scent Medea's Sunscreen, though it is unclear whether there are other kinds.

The Sea of Monsters
In The Sea of Monsters, Annabeth suggests using this to fight the Colchis Bulls saying that if you don't use this while fighting them you'll get burnt to a crisp, before realizing that she left it at home.

The Demigod Files
In the photo of Annabeth's trunk, Medea's Sunscreen is shown.

The Lost Hero
When Leo tells Medea he doesn't need fire protection she wonders how since she sees he isn't using her trademark sunscreen.

Use
When SPF 50,000 is used, it makes the user invulnerable to certain types of fire. It is probably used regularly by demigods when going on quests.