If you’ve ever uttered the phrase “It’s not the heat, it’s the humidity,” you might be from North Carolina.

Summer packs a powerful punch in North Carolina, but heat is only half the battle, the humidity can make already high temperatures seem suffocating.

Because humans produce sweat to control body temperature and cool the body when it gets too hot, drier air feels less oppressive than more humid climates. As humidity climbs, sweat becomes a less effective means to cool down.

“When you perspire, the sweat on your skin evaporates and this process cools the body,” says Meteorologist Gary Stephenson. “Think of when you step out of the shower. You feel cooler. This process is called ‘evaporational cooling’.”

Interestingly, humidity actually tends to be higher in winter months than spring and summer in North Carolina.

“It’s easier to saturate the atmosphere when the temperature is 40 degrees compared to when the temperature is 85 degrees,” Stephenson says. “But remember, 100 percent humidity on an 85-degree day is much more uncomfortable than 100 percent humidity on a 40-degree day.”

When high heat and humidity combine in summer months, it can become dangerous to people and animals who spend long periods of time outdoors. Farmers and farm workers are at high risk for developing heat-related illnesses.

“What we have found is that farmers often experience symptoms of heat related illness but do not connect the symptoms with being too hot,” says Robin Tutor, Interim Director of the N.C. Agromedicine Institute. “A major issue is that by the time a person stops sweating they are significantly dehydrated and at risk for irreversible damage.”

Dangers of heat include heat cramps, heat syncope or fainting, heat exhaustion and heat stroke. The best ways to avoid becoming a victim to extreme heat are to drink plenty of water and take plenty of breaks in the shade or indoors. If dizziness, light-headedness, nausea or headache occur, or perspiration stops, it’s time to seek medical attention.

People who work outside during hot summer months should stay tuned in to local weather reports and take extra precautions to be sure they are prepared to stay safe in dangerous temperatures.

The Department of Labor notes that farmers and factory workers who are not acclimated to working in hot weather are more likely to succumb to heat-related illnesses. In addition to following standard guidelines for safety in high temperatures and humidity, those who work in extreme conditions can help protect themselves by acclimatization, or short exposures followed by progressive adjustments over a period of time.

“And don’t forget about the critters,” Stephenson says. “Animals are susceptible to heat injury just as humans. Make sure they have plenty of water and a shady spot as well.”

“That old saying ‘it’s not the heat, it’s the humidity,’ is so very true,” Stephenson says. “At 95 degrees, if the humidity is low, your body can cool itself. If the humidity is high, it’s not going to cool as effectively and you’re going to feel uncomfortable.”

But comfort in the heat is a relative thing. “What’s comfortable is whatever you’re used to. If you’re used to a humid environment, you’re comfortable,” says Stephenson. “Now when the air temperature crosses 100 degrees, that saying goes out the window no matter what the humidity!”