1) Carry exact change for bathroom access
Staying well hydrated helps acclimatization & jet lag adjustment. It also necessitate many visits to the bathroom. Many bathrooms change and require exact change to enter. Having the right coin is critical. Small bills are also helpful for similar reasons in the Tokyo subway where credit cards are not taken.
2) Use Cough drops at high altitudes
High altitude air is dry & cold. Eating cough drops are a good precaution. Cough drops are tasty (Ricola), reduce coughs, and avoid dry mouth. Hard candies are a good alternative but not as beneficial for the dry air.
Stray dogs are smart, canny, and can be common outside the US. They also have keen senses of smell. I would not recommend leaving a pack unattended- even if it is only 10 feet from you. I left my pack unattended in a parking lot near the Izta trailhead much to my chagrin.