5 Reasons the Humidity Can Be as Risky as the Heat and What to Do About It

It’s summertime, and the living is muggy. As temperatures continue to escalate around the globe, there is an increased risk of health problems due to extreme temperatures. When it’s between 105 and 130 degrees Fahrenheit, heat exhaustion becomes likely. Anything above that and you could experience heatstroke. 

Heat isn’t the only warm-weather environmental factor that puts you at risk. It’s also the humidity. According to Healthline, if the outside temperature is 85 degrees Fahrenheit with 80% humidity, it feels like 97 degrees. Not only does humidity increase the intensity of outdoor heat, but it also makes the air more dense and can affect everything from how you sweat to how easy it is to breathe.

Dry heat vs humid heat

There are dangers to both dry heat and humid heat. Dry heat, as the name suggests, is a type of heat that lacks moisture. When you step outside in these conditions, it can feel like you just entered a sauna. In this type of heat, you’re more likely to become dehydrated. Dry heat can also be hard on your skin and create dry nasal passages. 

Humid heat indicates conditions where the air is full of water vapor. When you step outside during periods of high humidity, the air is sticky and dense on your skin. You might feel like you just stepped into a steam room. As NASA explains, when the atmosphere is already full of moisture, it doesn’t have the capacity to hold more. This causes water to evaporate more slowly — including your sweat. 

Areas with dry heat include desert regions like Arizona, Nevada and inland California. Meanwhile, the midwest and eastern United States are likely to experience more humidity because it rains more often. Parts of the southern United States can also become quite muggy during certain seasons. 

1. Overheating is more likely in high humidity

Your body typically cools down by sweating. You release sweat from your pores, your capillaries expand in reaction to your cooler skin and your temperature starts to go down. Because water evaporates more slowly in humid conditions, your body can’t rid itself of sweat. This messes up the entire process. 

If you’re not getting any relief from sweating, move to the shade or go indoors as soon as possible. A cold compress on the back of your neck may also help cool your body. Drink as much cold water as possible. When you’re active outdoors during a heat spell, the CDC recommends drinking 8 ounces of water every 15 to 20 minutes.

2. Humidity can also contribute to dehydration

While dry heat is known for leading to dehydration, so can humidity. Just because your sweat is not evaporating as fast doesn’t mean you’re not losing moisture. As the Medical University of South Carolina points out, high heat and humidity can also lead to a loss of electrolytes. In other words, you can become drained of essential salt and potassium. 

Drinking water throughout the day is the best way to prevent dehydration in hot and humid conditions. Sports drinks with electrolytes may expedite hydration. Given that you will become more dehydrated under direct sunlight, consider engaging in outdoor activity outside the hours of 10 a.m. and 4 p.m., when UV rays are strongest. 

3. Humidity often leads to significant body strain

When humidity interferes with your body’s ability to cool down, your systems go into overdrive to try to bring your body temperature down. The World Health Organization warns that when your body is strained during attempts to cool down, it can place major stress on organs like your heart and kidneys. If you have chronic conditions ranging from cardiovascular to mental health issues, humidity-induced stress could make them worse. 

If you start to overheat, slow down. Stop rigorous activity and make an effort to rehydrate. Sitting down or lying down can help you recover. 

4. Humidity may lead to mold growth

When the air inside your home becomes humid, you’re more likely to experience a mold problem. A warm, damp environment encourages this type of fungus to thrive. Mold growth can lead to various health problems, most commonly respiratory problems and allergies. 

The United States Environmental Protection Agency recommends keeping your home’s relative humidity between 30 and 50% to avoid mold. You can do this by using dehumidifiers and air conditioners. If you think you have a mold problem, call in a professional who can test for it and recommend a remediation plan if necessary. 

5. Airways can be affected by humidity

People with certain lung and respiratory illnesses may react as strongly to humidity as they do to heat. Patients with asthma, for instance, might experience bronchoconstriction from the increase in humidity. This narrowing of the airways could induce wheezing, shortness of breath and other symptoms. If you have chronic obstructive pulmonary disease, your breathing may also become more labored in humid conditions. 

If you have a respiratory illness, limit your time doing strenuous activities outdoors when humidity is high. Take breaks in air conditioning after a couple of hours. 

How to cope with high humidity 

If you live in a high-humidity area, make a plan for dealing with particularly muggy days. It’s important to have a coping strategy when outdoors and trying to get enough sleep on hot summer days. 

• Invest in air conditioning. Even a window or portable air conditioning unit can help you cycle some humidity out of a room. Dehumidifiers in the bedroom can also make sleep more comfortable. 
• Plan activities early in the morning. Instead of a noon run, consider getting up early and returning home before 10 a.m. Heat and humidity often spike in the middle of the day. 
• Keep hydrated. Perhaps the most important way to stay safe during a stretch of humidity is to stay hydrated and make sure you have enough electrolytes. Drink one cup of water every 15 minutes or so if you’re active outdoors. 
• Wear clothing that breathes. Because the risk of overheating is so high, humid days call for moisture-wicking clothing that allows for air flow. Cotton, nylon and linen are three good fabric options. 
• Carry a fan. A chargeable pocket fan is an excellent addition to your purse or glove box. You can pull it out as needed for a quick cool down. 
• Avoid using your oven. Heating up your kitchen can offset the benefits of your air conditioning. Switch to an air fryer or crock pot on hot days. Better yet, prepare foods like salad or cold pasta that won’t leave your kitchen steamy.