Different folks have different needs . . .
We ride extensively in the desert southwest (Arizona). We ride 'in tandem' at least 5 days a week.
Pilot (guy) does not use sunscreen unless he'll be out for over 4 hours and then only on his nose and tips of ears.
Stoker (lady) always uses sunscreen and has sensitive skin.
Pilot wears cycling cap under helmet; stoker wears short visor on helmet.
Both wear corrective sun sensor lenses.
Suggestion to wear a wet bandana and cycling cap are great but depending on heat/humidity level . . . this can be bone dry in minutes here in AZ.
Have ridden in temps as high as 117 degrees and 2% humidity . . . not recommended, but do-able with proper hydration.
Sunscreen (NOT sunlotion) is good, lots of water is good. So is light colored/looser fit clothing.
Enjoy the tour and don't over-worry!
Pedal on!
RUdy and Kay/zonatandem