As a kid you must have heard “put on your sunscreen,” or “you can still get burned on a cloudy day.” These admonitions apply doubly when working outdoors, regardless of the season—but they’re especially true in the summer.

Mild exposure to the sun’s rays can help increase vitamin D production in the body and make you feel good. Too much sun, on the other hand, can result in prematurely aged skin, sunburn, heat illness, and even cancer.

Below are some expert-recommended ways to keep yourself (and your employees) safe from scorched skin—and other serious consequences of working in the heat and sun.

Preventing and Treating Sunburns

Sunburns aren’t just itchy and painful. They can result in blisters and peeling skin, and can even even lead to abnormal growths and cancer.

The skin has ways of telling you that it’s in danger. If it feels warm to the touch or begins to turn red, it’s time to get out of the sun, says Angela Robles, a master esthetician based in Woodland Hills, California. If you have to stay outside, Robles notes that sunscreen is an excellent line of defense. She recommends using a formula that is water-resistant and has an SPF (sun protection factor) of 30. (Clothing can also protect you from the sun, but its effectiveness depends both on the material and color of the fabric.)

A few other notes about sunscreen:

1. SPFs higher than 30 aren’t worth it.

If you’re thinking about purchasing a sunscreen with an SPF of 50 or 60, Robles says not to bother. According to Robles, “There is no real benefit to using an SPF over 30,” as formulas with higher SPFs only offer a “smidge more protection.”

2. Certain types of sunscreen are better than others.

Robles also recommends using sunscreens that contain zinc oxide and/or titanium dioxide. These formulas are known as physical blockers because they reflect UV rays away from the skin, while other formulas (chemical blockers) absorb and neutralize them. “Dermatologists overwhelmingly recommend physical blockers as opposed to chemical ones,” says Robles.

3. Apply sunscreen liberally to anywhere the sun’s rays might hit.

Robles notes that the back of the neck and ears tend to get sunburned more frequently simply because people forget to apply sunscreen in those areas.

4. Don’t get lazy about sunscreen just because you’re not in pain.

The full effects of a sunburn often occur after the exposure to the sun has stopped. Symptoms like swollen skin, headache, and fever usually start about four hours after sun exposure and can continue to worsen for 24 to 36 hours.

Skin peeling usually begins three to eight days after exposure, according to the U.S. Center for Disease Control and Prevention. If blistering occurs, cover the blisters with gauze but don’t break them, as this can lead to infection. To ease sunburn pain, take cold baths and apply aloe gel or lotion or hydrocortisone cream to the skin.

OSHA Recommendations

OSHA provides recommendations for keeping workers safe in high-heat conditions—and they go way beyond sunscreen. In 2011, the organization developed the Water.Rest.Shade campaign. It aimed to raise awareness about various types of heat illnesses, including heat stroke (when the body is unable to rid itself of excess heat), heat exhaustion (the result of heavy sweating), heat cramps (loss of body salts and fluid during sweating), and heat rashes (skin irritation caused by sweat).

Many workers get sick or even die every year while working in extremely hot or humid conditions, and more than 40 percent of heat-related worker deaths occur in the construction industry, according to OSHA officials.

Although there are currently no national OSHA standards for occupational heat exposure, employers are required to provide their employees with work spaces that are “free from recognizable hazards that are causing or likely to cause death or serious harm to employees.” Therefore, the campaign reminds employers that they must provide outdoor workers with water, rest, and shade in addition to planning for heat-related emergencies. They must monitor workers for signs of heat-related illness, which can include confusion, fainting, seizures, dizziness, weakness, muscle cramps, headache, nausea, vomiting, or high body temperatures.

Depending on the specific activities you engage in out in the field, you can reduce your chances of falling victim to heat-related illnesses by wearing insulated gloves, reflective clothing, or a plastic jacket with pockets that can be filled with containers of ice.

For more information regarding symptoms and signs of heat-related illnesses, check out OSHA’s Occupational Heat Exposure page.