Americans looking to enjoy their summer outside after a pandemic year now have other threats to worry about.

The big picture: Experts are warning that ticks are on the rise and poison ivy may be more abundant this year. That means hikers, campers and anyone else excited to get outside after months of pandemic confinement should take extra precautions to avoid both.

Driving the news: Winter and spring seasons across the U.S. are becoming warmer due to climate change, creating conditions ripe for ticks and poison ivy to thrive.

Ticks are more active and abundant than usual, largely due to a mild winter, early spring and heavy rain season in parts of the U.S., according to the Weather Channel.

• "This year, most of the country fits the bill, but the Midwest is a 'tick time bomb,'" Weather Channel meteorologist Domenica Davis said last month.
• "Warm, wet weather will allow the pest to persist and even pop up in places where they're not usually found," she added.

By the numbers: Approximately 30,000 cases of Lyme disease — which is caused by a bacteria spread by some ticks — are reported to the Centers for Disease Control and Prevention by state health departments each year.

• Yes, but: The CDC notes that the number is far higher: "Recent estimates using other methods suggest that approximately 476,000 people may get Lyme disease each year in the United States."
• Symptoms of Lyme disease depend on its stage, but can include, fever, chills, rash and muscle and joint aches.

Poison ivy, meanwhile, has become more widespread and toxic in recent years due to higher levels of carbon dioxide, researchers have found.

• "An abundance of poison ivy can be detrimental to forests and nature areas, too. As it continues to grow and expand, it could potentially dominate the native vegetation and become a management concern," the Detroit Free Press reported last month.
• "More carbon dioxide in the air just makes photosynthesis in general easier ... The process is more efficient. That means essentially, all plants are bigger, bigger leaves, more productive," Katie McGlashen, a park interpreter for the Eddy Discovery Center at Waterloo Recreation Area in Michigan, told the Detroit Free Press.

By the numbers: Approximately 85% of the U.S. population is allergic to poison ivy and other similar plants, and about 15% are extremely allergic, per the American Skin Association.

• Once skin comes in contact with poison ivy, it can lead to rashes, swelling, itching, bumps and blisters, according to the CDC.

How to protect yourself:

• The FDA recommends that people learn what poison ivy looks like to correctly identify it: "Each leaf has three glossy leaflets, with smooth or toothed edges. Leaves are reddish in spring, green in summer, and yellow, orange, or red in fall. May have greenish-white flowers and whitish-yellow berries."
• To avoid ticks, the CDC says people can treat their clothing with products containing 0.5% permethrin. You can also use EPA-registered insect repellents.
• Avoid contact with wooded and brushy areas with high grass and walk in the center of trails. Shower soon after being outdoors to reduce the risk of getting rashes from ivy or tick-borne diseases.
• Check your clothing, gear and pets for ticks and remove them if spotted — never squeeze a tick to remove it, as it could worsen any infection.
• If you suspect you've been in contact with poison ivy, immediately wash you gear and clothing. Wash your pet with rubber gloves to avoid exposing yourself to plant oil, which can linger on surfaces for months.
• Contact your doctor or other health officials if you are concerned about possible exposure.

The bottom line: Don't let your guard down this summer just because you made it through a global pandemic.