Hello Alister,
Is your brother receiving treatment for his MDS? Night sweats can be a side effect of the chemo treatment when you are in your nadir. My husband experienced night sweats during the first few rounds of Dacogen. Someone on the forum recommended pomegranate juice and we must admit that it has worked for my husband. Also, clothing that will wick away sweat may help.
He should report this and other symptoms to his doctor. Our doc always asks about night sweats. It sounds like he should also be checking his temperature for a fever. We have been instructed to report to the hospital for a temperature of 100.3 or above.
I hope this helps.
Best wishes,