Any Builders out there taking Aza? Worried about sun exposure

Hi,
Just wanting to hear from others in the same position.
My husband is a builder and does long hrs (physical work) in the sun.
He was diagnosed 2 yrs ago with Crohns.
He started on Pentasa but had a terrible heart reaction ( myocarditis and pericarditis ) and is now currently on Azathioprine 100mg daily
Every day is a constant worry about the amount of sun exposure and skin cancer risk.
He completely covers his skin with clothing,also sun cream on any other exposed skin ( face, hands etc ) it's just not practical to reapply multiple times a day once he starts working in a dirty/ dusty environment.
He has skin checks 6monthly but the concern won't go away.
He is considering changing careers ( regrettably )
Can anyone offer ther advice / story
Thankyou

Not a builder and not on Aza. But I am taking a medication that makes me sun sensitive and I have had melanoma--so I stay out of the sun or wear lots of sunscreen or sun protective clothing.
There is a company that makes sun protective clothing--the cloth really works--however, it does make one look a bit goofy. I have gotten over this and when we had an outbreak of West Nile Virus from mosquitos a few years ago, people stopped me in the street thinking that I was wearing mosquito protection and they wanted to buy some! http://www.sunveil.com
Some sporting goods stores also carry sun protective clothing.
Perhaps there is an occupational health and safety person that could help him out?

Thanks Happy, will check it out.