What is the highest dose of restoril (temazepam) you can take without overdosing?

No easy answer. It depends on your age, size, and general health. Also, "overdosing" isn't a sharp line crossed at one exact dose... There are mild overdoses, severe overdoses, and lethal overdoses. In general, adults shouldn't exceed 30 mg at a time. Taking more than this may result in deep or prolonged sedation, temporary confusion or delirium, and at higher doses, respiratory depression and death.