Here we are only slightly cold, taking a short walk around Cusco. Our hotel was within 1 block of this central square, where the Cathedral is located. On our way back from this walk Peter felt the effects of altitude. Coupled with the fact that we had not eaten, and he had not kept up his water intake we had a few scary moments. Later when we were on tour through the Cathedral, he had to have an oxygen mask. Going from our home in Lima, elevation about 400' to Cusco, over 12,000' definitely slowed all of us down.
The greeting at our hotel began with an invitation to have some coca tea. This, we were assured, was not addictive, yet we declined. The next morning we had some, but honestly, didn't notice that it helped. As for addictive, it might not be physically addictive, but it did appear to create a habit, much as my own love hate relationship with my morning coffee.