"Create a warm air current with fire energy."
Thermal is Mars-based utility psynergy in Golden Sun: Dark Dawn. Its encyclopedia entry says the following: "This fire-based Psynergy creates a warm updraft strong enough to lift the user up to otherwise inaccessible heights."
Thermal is exclusive to Eoleo, and costs 3 PP per use. This form of psynergy is used on blocks that are emitting spiraling flames, so the flames can be used as updrafts so the player can ascend when he walks into it. This form of psynergy is first accessible at Belinsk after recruiting Eoleo, but a current does not appear until you reach Champa.