Sweating it out in the heat on a jobsite is no fun and can even be dangerous, which is why it’s so important for employers to have a heat illness prevention plan. But heat-related illness isn’t the only thing to worry about come summer, as a recent hazard alert from CPWR–The Center for Construction Research and Training reminds us. Skin cancer is another.

A 2017 study in Britain, hardly known for its sun, found that 2 percent of all cases of malignant melanoma — the deadliest form of skin cancer — came from occupational exposure to the sun, and that construction workers accounted for the largest proportion of these cases.

Think what the numbers might be in, say, Arizona, California, Texas, Nevada or Florida. In the United States, more people are diagnosed with skin cancer each year than all other cancers combined. According to the American Cancer Society, men 49 and under have a higher likelihood of developing melanoma than any other cancer.

Since the vast majority of skin cancer cases are caused by exposure to ultraviolet (UV) radiation from the sun, outdoor workers should take heed. And, since employers are responsible for providing a safe work environment, so should they.

Construction workers can be exposed to UV radiation even when working in the shade. That’s because it can be reflected from nearby surfaces, including sand and concrete.

To help protect workers from skin cancer, start with these strategies.

Remind workers to use sunscreen, even when working in the shade and on cloudy days

They should choose a water resistant, broad-spectrum sunscreen with an SPF of 30 or higher, apply it liberally, and reapply it every two hours, especially when sweating. The lips need protection, too. (Sunscreen or a lip balm with SPF protection will work.) Men are notoriously bad about wearing sunscreen, which explains in part why more men than women are diagnosed with melanoma. A strong push from their employer might help. Try to make wearing sunscreen part of your corporate safety culture.

Have them dress to protect

Workers should cover up with long sleeve and pants and choose fabrics with a dense weave. They should use brims, covers or flaps that attach to their hard hats to protect the face and neck, and wear wraparound sunglasses, when appropriate, to protect the eyes. Check your safety glasses to see if they offer UV protection.

Erect temporary shade structures

Shade isn’t foolproof but it’s much better than working in full sun.

Time outdoor work right

Get as much of it as possible done when the sun is weakest, usually before 10 a.m. and after 4:00 p.m.

Make skin cancer protection the subject of your next safety talk. Hang a skin cancer prevention poster or the CPWR hazard alert in your job trailer. Let workers know that the Skin Cancer Foundation recommends doing monthly head-to-toe self examinations so they can spot any suspicious growths or changes early — and that yes, even people with dark skin can and do get skin cancer.

RELATED: Good Construction Safety Meeting Topics for Summer

According to the American Academy of Dermatology, warning signs include changes in the size, shape or color of a mole or other skin lesion, the appearance of a new growth, or a sore that doesn't heal. Anything changing, itching or bleeding should be looked at as soon as possible by a dermatologist.

You might consider bringing in a dermatologist to give a presentation and explain the signs of skin cancer to look for, since skin cancer is much more treatable when caught early. Or even have a dermatologist come in and provide free skin cancer screenings. The American Academy of Dermatology is a good resource to start with.

Marianne Wait is an editor and writer who creates content for Fortune 500 brands.