Most Vedic gods are powers. The Ashvins are helpers, and what the hymns to them mostly contain is a catalogue of people they got to in time. Bhujyu is cast away in the sea and carried home. Chyavana, worn out with age, is made young again. Vishpala loses a leg in battle and is given one of iron. Atri is brought out of a glowing pit. Rijrashva, blinded, is given back his sight. The list runs to dozens of names, many of them attached to nothing else in the collection, and the poets recite it the way one recites a reference: these are the things you have done, do them for us.
The pattern inside the catalogue is consistent enough to be the point. In every case the person is already lost when the twins arrive. They are not asked to prevent a disaster; they are asked to reverse one, and the reversals are physical and specific, a limb, an eye, a body pulled out of water or fire. That gives them a role no other Vedic god quite occupies. Indra wins, Agni carries, Varuna binds and looses, and the Ashvins turn up at the last possible moment with a repair.
Their equipment matches the job. The chariot is three wheeled and has three seats, moves faster than thought, and is described as going over land, water and air alike. They travel at dawn, are invited to the first pressing of the soma, and are closely tied to Ushas, whom they follow or accompany. Honey belongs to them: they carry it, they pour it, and the word for it runs through their hymns. A tradition that later hands them the invention of medicine had a good deal of material to work from.