At high temperature, para hydrogen is :

At high temperature, para hydrogen is more stable than ortho hydrogen.

When both nuclei of a hydrogen molecule are spinning in the same direction, the molecule is said to be ortho hydrogen.

Para hydrogen is the hydrogen molecules in which both of the nuclei are spinning in the opposing directions. At $0^{\circ }\mathrm{K},$ para hydrogen, is more stable and makes up the majority of hydrogen. 

Ortho and para hydrogen are distributed in a 1 : 1 ratio at the temperature at which air liquefies. The proportion of ortho to para hydrogen is 3:1 at room temperature. The ratio of ortho to para hydrogen can never be greater than 3:1, even at very high temperatures.

Hence due to above reasons at high temperature, para hydrogen is more stable than ortho hydrogen