Hey Aashi,

AMS or Acute Mountain Sickness is a usual situations when you travel to destinations of higher altitude.

Here is how you can prevent yourself from AMS in Spiti Valley.

-Increase the altitude gradually.

-Keep yourself hydrated. Avoid overhydration.

-Avoid over exertion.

-Avoid Tobacco, Smoking, Consumption of Alcohol and other depressant drugs.

-Keep your body warm.

-Carry preventive medicines for AMS.

(Medicines like Diamox could be taken but only after consultation from a doctor or physician.)

-Immediately descend if the symptoms increases.

Hope this answers your query.

Have a good day!