Zuhd is detachment from this world in the spiritual sense and not in physical sense. On a very hot summer day in tropical climate if you drink water with the intention of quenching your thirst but with firm belief that water does not do the job of its own but by Allah (SWT)'s permission only then you are in the state of Zuhd. I once ended up at dinner with Hazrat Qari Amir Hasan Sahab (RA) and my Shaikh (DB). Both of them are merely half a naan (the bread, chapati made of fermented flour) together, not separately. For me this is high enough level of Zuhd. And Allah (SWT) knows the best.