Makeup artist Ashunta SheriffIn case you haven't noticed, there's a nationwide heat wave going on this week. If your makeup starts sliding the minute you walk outside, don't sweat. There's a way to keep it in place in the face of heat and humidity, according to celebrity makeup artist Ashunta Sheriff. Read on for her advice.

It's prime time
"Definitely start with a foundation primer," Sheriff says. (She recommends Mary Kay Foundation Primer.) "That's going to keep the makeup on through the heat, tone down redness, and make the makeup last." Speaking of makeup, she adds, less is more when the temperature soars. "Don't wear a bunch of foundation and concealer," she says. "Go with tinted moisturizer and apply concealer only where you need it."

Choose products wisely
One way to keep makeup from sliding off? Use powder formulas when possible. "During the summer, stay away from cream cheek and eye colors," Sheriff advises. "Otherwise, you're going to look like you have wet, oily eyelids." The exception: if a cream eye color specifically says that it's waterproof and dries into a powder finish, you're good to go.

Go waterproof
"Use waterproof mascara, especially in July and August when it's extremely humid and hot," Sheriff says. "Regular mascara tends to flake off and rub off." If you usually wear multiple coats but don't like waterproof formulas, Sheriff advises "sealing" your usual mascara with one coat of a waterproof one.