I did think about that too. My perception of pain as a kid is different than it is now. However, if it's true that he's having difficulty breathing (my presumption only), then he's in medical need.<quoted text>
You would know best about pain levels, but if he thinks his is a ten already, I'm believing his pain threshold is very low. He took one dose of chemo and begged out. From the people I know, the first one usually isn't that bad. A few doses down the road is when you really start to feel it.
The first and last rounds are the "worst" for different reasons. You don't know what to expect with the first one, and it may be harder on the body than imagined. However, it's true that with each round, it wears the body down more and more.