I was there for a 2 week raft trip a few years back,,,in summer along the C. river it was over 120F in the SHADE, and 36F in the river below the first dam,,,and i got a super duper bad rash case for the full two weeks on the first day. Neither the espensive outfitter "we don't want to scare people away" nor the NPS warned me in advance, so i could have brought some TECNU white liquid soap from home to wash with daily and prevent a trip of a lifetime from being the most miserable physically painful "vacation" i had ever taken !!
PLEASE SAVE YOURSELF THE RED RASH AND BLISTERS FOR 2-3WEEKS AND LEARN WHAT IT LOOKS LIKE ,,,BEFORE YOU GO TO ANY NATIONAL PARK, ESPECIALLY "GRAND CANYON NATION PARK",,,AND IF YOU WANT TO BE SAFE AND PROTECTED IF YOU DO ACCIDENTALLY TOUCH THE PLANT AND CONTAMINATE YOUR DELICATE SKIN AREAS, AHEM, WITH THE OIL,,,THEN BUY SOME "TECNU" ,,,BEFORE ,,,AND USE IT EVERY DAY WITH JUST A FEW DROPS ON A SOAPY WASH CLOTH.
HAPPY HIKING !!