My gut instinct is to say:

If the windings are the same gauge wire, then the length of the 24V winding must be longer, and so the resistance would be more, and the current reduced.

Say 12V is 2A, therefore the resistance must be 6?

At 24V 1A the resistance would be 24?, so 4 times longer.

P=I²R, so 2²*6 = 24W

P=I²R, so 1²*24 = 24W

The two motors are the same power rating, but the mass of the 2A one will be smaller, so the heat will be more concentrated. The amount of heat energy will be the same, but the heat per square inch will be greater in the smaller motor.

The higher current motor will have more torque than the lower current one.

?=kt?I

kt is a constant, ? is the torque