Talk to General Physician on Sweating

My brother is a hydrocaphlus patient he's been born with it had a lot of complications as a kid at 14 he had seizures doctors prescribed him lerace and epivol and he's been taking these since he's on a wheel chair He recently got all his tests done including thyroid, cbc, hba1c, liver, kidney functions everything was normal except he was low in vitamin D, so as we live in karachi it's already really hot in here since last two nights he's been having night sweats like not on all part of his body but only the side he sleep on would be all sweaty and the sheet would be drenched is it OK? Or should we be worried?