Summer temps can exacerbate swelling in the feet. Hydration and exercise are key tools in alleviating symptoms. (For Spectrum Health Beat)

It’s a hot summer day and you’re soaking up the sunshine in your backyard.

As the day goes on, you notice your feet and ankles swelling. Maybe your shoes feel tighter when you go to put them back on. Or maybe your feet are visibly puffy.

What’s going on? Should you be worried?

Actually, it’s your body doing its job of trying to cool you down, according to Marisha Stawiski, DPM, a podiatrist with Spectrum Health Medical Group.

“When your body heat goes up, your blood vessels constrict to try to cool the body off,” Dr. Stawiski said. “Then it’s harder for the fluid to get back up to your heart.”

Add in the effects of gravity in your lower extremities trying to pull the fluid down and you get fluid pooling around your ankles and feet. This leads to swelling, also known as heat edema, Dr. Stawiski said.

Some people have medical conditions that cause edema year-round, but everyone is more prone to it in the heat of the summer, even if you don’t have other contributing factors, Dr. Stawiski said.

If you notice swelling in your feet or ankles, she suggests talking to your doctor.

It could be caused by medication—especially medication for high blood pressure—or a chronic illness such as congestive heart failure, liver disease or kidney disease. It might also stem from an issue with your veins, including chronic venous insufficiency or varicose veins.

As anyone who has endured a third trimester of pregnancy during the summer likely knows, pregnancy also causes swollen feet. It’s from extra fluid in the body and pressure from the growing uterus.

“The same principles apply, they’re just magnified during pregnancy,” Dr. Stawiski said. “It is definitely a big issue for a lot of women.”

Age can also make things worse, in part because of increased venous insufficiency but also because of medical conditions such as hypertension, which increases with age. Taking more medications can also be a contributing factor.

One red flag you should never ignore: sudden onset of swelling in one leg, along with pain. This could signal a blood clot, which requires emergency treatment.

But if your swollen feet and ankles happen occasionally throughout the summer and you’re a relatively healthy person, it’s likely not a red flag—and it’s probably the result of summer temps.

The good news: There are tips that work to reduce the swelling and, hopefully, prevent it.

Stay hydrated

Some patients think that if their feet are swollen, they should not drink more water, Dr. Stawiski said.

Nothing could be further from the truth, she said.

“Especially in the summer, you can get dehydrated,” she said. “Swollen feet don’t mean you have too much fluid, it just means it’s in the wrong place. So you definitely want to stay hydrated in the heat, even if you’re swelling.”

Aim for eight to 10 glasses a day, and even more if you’re sweating a lot.

Avoid foods high in sodium

Dr. Stawiski recommends avoiding high-sodium foods.

Eat more foods that are good diuretics, as they help eliminate excess fluids from the body. This includes fiber-rich fruits and veggies.

“Make sure you’re eating a healthy diet with lots of greens and veggies because that will help in a natural way to process all that fluid,” she said.

Stay active

Exercising regularly and staying active throughout the day helps our bodies and our lower extremities, with the natural pumping of veins.

Don’t stay in one position for too long. Instead, go for a walk or swim to promote circulation and release the fluid buildup.

If it’s too hot to exercise outside, go to a mall or air-conditioned place where you can be active and stay cool.

Staying active can also help you maintain a healthy weight, which reduces the risk of swollen feet and ankles.

Elevate your feet

While activity is important for prevention, you should also watch for any swelling. If you notice swelling, you can help relieve it by elevating your feet above your heart.

Lie on your back with your feet elevated for a short period of time—around 20-30 minutes—and then get up and move around again.

Stay as cool as possible

Avoid things that raise your body temperature, such as hot baths and saunas. Find methods to stay cool. Sit in the shade or move into air-conditioned spaces when possible.

Avoid drinking too much alcohol

Alcohol can dehydrate your body and cause you to retain more fluids.

Up your magnesium

Check with your doctor first, but a magnesium supplement could help prevent swelling by reducing water retention, Dr. Stawiski said.

You can also boost the magnesium naturally in your diet with pumpkin seeds, almonds, cashews, peanuts, spinach, black beans and edamame.

Wear compression stockings

It’s tough to wear compression stockings in the summer, but if you’re in a profession that requires you to be on your feet or sit in one position all day, it’s a good idea to wear them, Dr. Stawiski said.

“They help to push that fluid up,” she said.

When in doubt about your swollen feet and ankles, don’t hesitate to reach out to your primary care doctor or a podiatrist.

“Your doctor can help determine whether it’s caused by anything underlying,” Dr. Stawiski said. “And if it’s just coming from the heat, then we can help explain that there are things you can do to prevent it.”