Key Takeaways
- Humidity is the concentration of water vapor in the air. In humid environments, it is difficult for sweat to evaporate from the skin, making it more difficult for the body to effectively dissipate heat and cool down.
- High humidity combined with heat and other factors can cause symptoms such as dehydration and muscle cramps and increase the risk of heat-related illnesses such as heat exhaustion or heat exhaustion.
- To combat the humidity this summer, experts recommend increasing fluid intake, wearing light-colored clothing, and avoiding sunlight during peak hours.
As summer approaches and temperatures begin to rise across the United States, it's important to know how the weather can affect your health when planning your activities. You probably know that you need to be on guard for hot weather, but another factor you may not think of but is very important is humidity. This is a measure of the amount of water vapor in the air.
It may seem like a little bit of water in the air on a hot summer day would help, but meteorological reality is a little more complicated than that. High humidity and high temperatures can combine to create a dangerous mixture, said Dr. Kevin Lanza, assistant professor at UTHealth Houston School of Public Health.
“Humidity itself is less of a threat, at least at lower temperatures, but when combined with higher temperatures, hot and humid conditions, it can potentially cause problems,” Lanza said.
Here are the most important health effects of humidity you need to know, along with some expert-backed tips for coping this summer.
When is it unsafe to be outside in high humidity?
What level is considered unsafely high humidity varies from person to person, Dr. Shashank Ravi, clinical assistant professor of emergency medicine at Stanford Medicine, told Verywell.
Certain factors, such as your level of hydration, how long you are exposed to high humidity, and how active you are in these conditions, all play a role in how it affects your health. And it's not just when you're outside. Ravi said, “Indoors with high humidity and lack of air circulation can also be dangerous.”
Higher humidity levels, typically above 60% to 70%, can cause sweat to evaporate more slowly from your skin. David Cutler, M.D., a family medicine physician at Providence St. John's Health Center in Santa Monica, California, said:
Sweating inefficiently in high humidity “can cause people to feel hotter than they actually are,” Cutler said. “Higher humidity also increases the heat index, which is the perceived temperature. For example, if the actual temperature is 90 degrees Fahrenheit, high humidity can make it feel like 105 degrees Fahrenheit.”
On the other hand, low humidity of less than 30% to 40% can also have negative health effects by causing dry skin and respiratory discomfort. “Low humidity can dry out the mucous membranes of your nose and throat, increasing your susceptibility to irritation, coughing, and respiratory infections,” Cutler said.
According to Cutler, the best way to measure humidity levels is with a hygrometer. These devices, which have a digital readout or thermometer-like dial, display the ratio of humidity to the maximum moisture capacity of the air at the current temperature. It basically shows how much water is actually in the air compared to how much water is in the air at a certain temperature.
If you don't have a hygrometer to get accurate readings, you can also check humidity levels in a weather app or forecast website. Humidity levels fluctuate throughout the day and depend on other conditions such as rain.
How does humidity affect my health?
According to Lanza, the effects of humidity on the human body and health depend on how humidity interacts with temperature. Humidity itself does not pose much of a threat, especially at low temperatures, but when combined with heat, the effects can become serious.
Our body's thermoregulatory system plays an important role in maintaining our internal core temperature, and sweating is the primary way we cool ourselves, Lanza said. However, as mentioned earlier, humidity can actually slow down the process.
“As sweat evaporates from the skin, it cools the body and ultimately lowers internal body temperature,” Lanza said. “But on humid days, sweating does nothing to lower your body’s internal temperature. This is because sweat cannot evaporate easily due to the moisture in the air.”
High humidity can therefore cause health problems and even make individuals “more susceptible to health risks such as dehydration and fatigue,” Ravi added. Some situations that can arise when dealing with high humidity and heat include:
- dehydration: According to Ravi, high humidity can cause excessive sweating and cause the body to lose fluid more quickly. If water is not replenished quickly, symptoms such as fatigue, dizziness, and confusion may appear along with dehydration.
- Skin Rash: According to Lanza, humid environments can cause skin irritations like heat rashes and even fungal infections after prolonged exposure to heat and moisture. High humidity can also make skin oily and worsen conditions like acne, Cutler adds.
- crick: According to Lanza, in humid environments, people can lose too much electrolytes, which can cause muscle shock and cramps in the arms, legs or abdomen.
- Worsening respiratory disease: According to Cutler, high humidity can encourage the growth of mold, dust mites, and bacteria, which can worsen respiratory conditions such as asthma and allergies. Cutler added that thick, humid air can cause breathing difficulties and symptoms.
- Heat Exhaustion and Heat Stroke: According to Cutler, high humidity can increase the risk of serious heat-related illnesses, such as heat exhaustion and heat exhaustion, because the body's cooling mechanisms become less effective. If the body is unable to regulate its own temperature and begins to overheat, organ damage or even malfunction can occur.
Who is most at risk for heat-related illness?
According to Lanza, everyone is affected by extreme heat and humidity, but certain groups are more susceptible to heat-related illnesses than others.
- Young children: Children, especially infants and toddlers, have a smaller body mass to surface area ratio than adults, making them more vulnerable to heat stress.
- old man: Older people are at higher risk of heat-related illness and may be more likely to die due to age-related changes in their ability to regulate body temperature. As we age, our bodies produce less sweat, which affects our ability to cool ourselves in hot environments.
- Individuals with a pre-existing or chronic medical condition: People with chronic conditions such as cardiovascular disease, high blood pressure, and respiratory disease are more vulnerable to heat waves and related illnesses because they are less likely to sense and respond to temperature changes. People who are overweight or obese may retain more body heat, making them more likely to overheat.
- People taking certain medications: Diuretics, antihistamines, antidepressants, and other medications can interfere with the body's ability to regulate body temperature and increase the risk of dehydration.
- Individuals working outdoors: People who work outdoors, such as construction workers, agricultural workers, and landscapers, are at higher risk for heat illness because of the prolonged exposure to high temperatures combined with physical labor.
Early Signs Humidity Has a Negative Effect on Your Health
According to Ravi, it's important to recognize early signs that weather conditions like heat and humidity are affecting your health. Some early indicators that humidity may be affecting your health are similar to symptoms of heat exhaustion or heat stroke, such as:
- increased sweating
- heart racing
- Weakness
- fatigue
- difficulty walking
- dizziness
- headache
- nausea and vomiting
- crick
- faint
- In severe cases, confusion or changes in mental status
If you notice any of these early symptoms, Lanza recommends stopping physical activity, such as running or biking, or removing yourself from the situation that triggered your symptoms, seeking shelter in the shade or going indoors in a temperature-controlled, air-conditioned room. environment. You should also replenish lost fluids with cold water or sports drinks to restore electrolyte balance.
How to Stay Safe During Summer
With summer just around the corner, your best defense is to take proactive steps to prevent heat-related illnesses and the health effects of high heat and humidity, according to Lanza.
“The best way to prevent symptoms is to be proactive in how you prepare for the warmer months, especially May through September in the U.S., so you don’t even start,” Lanza said.
Here's what you can do to avoid putting your health at risk in hot, humid environments this summer season.
- Check the weather and humidity before going outside. Lanza recommends checking the weather no matter what your plans are. But definitely check it out if you plan on doing any outdoor activities. Knowing the forecast for heat and humidity can help you prepare and pack accordingly, including making sure you have plenty of water and sunscreen.
- Limit sun exposure/exercise during hotter times of the day. Ravi suggests avoiding being outside during peak heat times to reduce your risk of heat-related illness. If you plan to exercise, do it when the weather is cooler, such as in the early morning hours or late evening, to avoid the risk of overheating or dehydration, Lanza added.
- Relax in a cool or air-conditioned environment. If possible, resting and spending time in a cool or air-conditioned environment can help lower your body temperature, Lanza said. If you don't have air conditioning at home, try going to a local coffee shop, shopping mall, library, museum, or community center.
- Wear light-colored, loose-fitting clothing: Choose loose, lightweight clothing in bright colors to help keep your body cool, Lanza said. Fluffy, lightweight clothing allows air to circulate around your skin, allowing sweat to evaporate rather than being trapped.
- Stay hydrated: Lanza said it's important to drink plenty of water throughout the day to maintain hydration levels. Avoid drinks containing alcohol or caffeine as they can cause dehydration.
- Keep your social networks nearby: According to Lanza, many heat-related illnesses and medical emergencies occur because people are alone or unaware of their symptoms. Having social support nearby may mean that you have someone who can help you in case of an emergency or remind you to rest and hydrate.
What this means to you
Hot and humid environments can cause dehydration, muscle cramps, and heat-related illnesses such as heat exhaustion or heat exhaustion. Experts recommend staying hydrated, wearing light-colored clothing, and limiting sun exposure to avoid these health risks during the summer months.