Even in record heat, birdwatcher Theresa Erbstein pulls on pants before heading into the woods.
At Ridley Creek State Park, Erbstein set out during peak warbler season, choosing long pants over shorts as protection against ticks. The extra layer mattered, she said, even if it made an already hot day more uncomfortable.
"I will trek into anything, even in shorts, to get a picture of a bird, and I've gotten chiggers and ticks. I have a tick bite from early on in February already," Erbstein said.
The trip was partly successful. Erbstein didn't capture as many bird photos as she hoped, but she avoided any new bites. "The ticks are always bad," she said.
Health officials say those concerns are spreading across Pennsylvania. According to the Centers for Disease Control and Prevention, the number of ticks in the state is rising, with a 14-day average of 223 ticks reported in April - a level considered high for this time of year.
Emily Struckhoff, a vector-borne disease team specialist with Penn State Extension, said some of the most common ticks in the region are becoming active as temperatures climb.
"The black-legged tick or the deer tick, it's one of the most common species we have in Pennsylvania, it needs warmer weather to be able to come out and start looking for an animal to bite," Struckhoff said.
Struckhoff said ticks are expected to remain active through the spring and early summer. If a tick bites and remains attached, it can increase the risk of Lyme disease and other tick-borne illnesses.
"The sooner you can find it and take it off, the less chance there is that the bacteria can enter your body and possibly cause a tick-borne disease," she said.
Emergency room visits related to tick bites are also increasing. The current rate is about two-and-a-half times higher than the average over the past four years, underscoring the impact of the growing tick population.
Pet owners are taking notice as well.
Nathaniel Lee said he routinely checks his dog after walks in wooded areas.
"Muppet, as you see, he's very hairy," Lee said, gesturing toward his dog. "Sometimes I'll pull as much as eight off him."
Other hikers say prevention has become routine, even on hot days.
Elisabeth Deeb, hiking near King of Prussia, said she dresses with ticks in mind.
"I always wear pants and high socks just to protect my legs and stuff, and you always want to check your body afterwards," Deeb said.
Deeb and fellow hiker Lindsay Yohn said they came prepared for ticks, but the heat proved more difficult.
"As you can see, we are drenched," Yohn said.
Experts say awareness is key for anyone spending time outdoors. They recommend staying in the middle of trails when hiking, checking for ticks promptly after being outside, and removing any ticks as soon as possible to reduce the risk of disease.