Sure they can. Be aware of possible low BP more in the tub. Always have cayenne tincture in case they get faint. I'd do it on people with lower bp than that. My sister is rarely above 90/50, she otherwise fit. It is only in the text book you find normal as 120/80. It's about what is normal for you. I run 110/60. Just don't leave them alone, it is intense.