Chemo is very scary. My grandpa had lung cancer (which he survived and is doing well now and liking retirement), and one of the most surreal moments of my entire life was watching my grandpa cry in agony after receiving a treatment. That was the first time I had ever seen that, it was a mind-blower, it makes you realize how brutal that disease is. You just have to re-assure them that they're going to be OK. Just don't be discouraged if they vehemently disagree at first. Everybody handles it differently, too, and the anti-nausea drugs have been much improved.