What is "rigors"

Usage examples of "rigors".

The cult of Mithra, less widespread then than it has become since our expedition in Parthia, won me over temporarily by the rigors of its stark asceticism, which drew taut the bowstring of the will, and by its obsession with death, blood, and iron, which elevated the routine harshness of our military lives to the level of a symbol of universal struggle.

I spent a moment envying her leather trousers, which were withstanding the rigors of the wall-climbing far better than my own.