Should I Wear A Base Layer In Summer?

It’s time to start the grand debate: Will a base layer help to cool you down in the summer or just make you even more hot and uncomfortable?

Wearing a base layer in the summer will not cool your body down, but a base layer can improve wearer comfort, especially in humid conditions where evaporative cooling is less effective. Summer base layers should be lightweight, breathable, and made out of moisture-wicking materials which help regulate skin temperature.

That said, not everyone spending time out in hot weather likes the idea of wearing a base layer. Base layers are often tight and come in varying levels of breathability, so it’s possible that in some cases they aren’t the best idea when you want plenty of airflow.

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In order to help answer this question of whether or not a base layer is the best possible choice in summer, I reviewed studies on the helpfulness of base layers and sought out responses from hikers and backpackers with actual real-world experiences. Their opinions varied greatly, but I’ve compiled the general positions as clearly as possible.

What do you think? Do you like to use base layers when you’re out in the heat, or do you have your own solution to stay cool?

Continue on and you’ll see what we’ve how wearing a base layer in summer can be valuable, what base layers are best for warm weather, and more.

Does It Make Sense To Wear A Base Layer In Hot Weather?

Most of the time, when people think about adding base layers to their outfits, they’re thinking about staying warm in colder weather. When you’re battling the cold of winter, it only makes sense to layer up. On the other hand, it almost seems counterintuitive to add layers in the hotter seasons when you’re already trying to stay cool. However, a base layer might be more useful in hot weather than you might think.

Not all base layers exist for the sole purpose of keeping you warm. While they are often useful for maintaining warmth when you combine them with other clothing layers, base layers can also just be helpful for regulating your skin temperature. A solid base layer can also protect you from sunlight, which is so important for those who tend to burn easily (such as myself).

Additionally, base layers designed to absorb sweat are incredibly useful if you’re out hiking and know you’re going to be sweating more than usual. Sweat is uncomfortable, whether you’re in the cold or the heat. Although it may be less dangerous for your clothing to end up sweat-soaking in the summer, it’s still not fun.

Is a Base Layer the Coolest Option?

So, as far as your actual body temperature, base layers are not proven to actually cool your body down.

In fact, the coolest option has been shown in some studies to go without clothes, period. But, this option is not ideal. Whether you want to maintain some modesty or just follow the laws of the area, the next best thing is a base layer that is very lightweight. The breathability of a quality base layer can go a long way when it comes to keeping your skin temperature as comfortable as possible.

In short, unless you know you can go shirtless on a certain hike, a good alternative is to wear a thin, cool base layer.

This study suggests that the base layer should be of moisture-wicking materials (like wool or polyester) and should be loose to help evaporative cooling.

(Evaporative cooling is that phenomenon when you step out of the shower and you feel cold even though it’s warm in your house)

Will A Base Layer Really Make Me Cooler?

When it comes down to it, there’s little a base layer can do to reduce your overall temperature. If it’s hot outside, that’s just how it’s going to be. The goal of a base layer is just to help with keeping you more comfortable while you’re dealing with that heat.

There are a couple of ways base layers can do this. The first is that a good warm-weather base layer is typically designed to absorb sweat in a more efficient way than other materials. These layers get that sweat off your skin while also keeping it from reaching any outer layers you may be wearing (if you’re wearing one).

Secondly, a light, breathable base layer can allow you to stay as cool as possible without running around the woods in your birthday suit. While a base layer isn’t proven to reduce your overall temperature, it can help to keep your skin cooler.

Whether base layers help or not is actually controversial, believe it or not.

The Summer Base Layer Controversy

There can be a lot of debate when it comes to the effects of base layers versus other clothing types when you’re out in the heat. This study on indicates that the kind of fabric you choose to wear while hiking in a warm area may not make much of a difference. Meanwhile, another study from discovers that a base layer can provide a higher level of comfort than a simple cotton shirt.

Because there’s so much controversy over the topic, it can ultimately be up to each individual hiker to determine whether or not a base layer is necessary for the heat. Whatever keeps you the most comfortable is typically the correct answer.

In addition to your clothing, you may need some other tools for beating the heat. If you’re backpacking or camping, it may not be enough just to wear light, breathable clothing. In our article on staying cool while camping without electricity, we’ll give you 13 tips on how to stay comfortable when you’re camping in high temperatures. Check it out here!

In any case, there are a few key points if you want to try a base layer in the summer.

How To Select a Base Layer In Hot Conditions

Although there is some controversy about whether base layers really help, there are some things to look for in a base layer that can make a big difference:

  • Choose a loose base layer: This is the opposite of wearing a base layer in the winter. A loose base layer encourages evaporative cooling, which is the primary way you cool down in hot conditions (source, check out the full-text Discussion and conclusion to see more details about this)
  • Choose moisture-wicking materials: This can get complicated, but a sopping wet base layer made from cotton will increase the microclimate humidity which reduces evaporative heat loss, but a wet base layer improves heat conduction. Since evaporative heat loss is more important in thermoregulation, make sure to choose materials that don’t hold in moisture like wool or polyester.
  • Choose a base layer that is thin: Although insulation isn’t the primary purpose of a base layer, a thick base layer does provide some insulation. I can attest to this, wearing my thermal base layer when it’s warm out is not a fun experience.

How Do Other Outdoor Enthusiasts Feel About Wearing A Base Layer In Summer?

The opinions of other outdoor enthusiasts are as varied as the clothing options themselves. What works for each person is based on a number of variables including where they are hiking, the climate they are hiking in, whether or not they expect to sweat a lot, how long they are going to be hiking, and more.

I boiled down the responses into 3 categories:

ResponsePercentage of the total (37 respondents)
As Little As Possible35%
Shorts and T-shirt43%
Wicking Long-sleeve base layer22%
Short and t-shirt was the most possible option

The shorts and t-shirt category was the most popular, but about 40% of shorts and t-shirt wearers specifically mentioned that their t-shirt was moisture-wicking.

Hiking in a tank top is a popular option

Those who hike in a humid climate may be more likely to opt for a sweat-wicking base layer for the sake of avoiding sweat-soaked clothing. On the other hand, hikers who spend more time in deserts may not worry as much about sweating too much since their sweat will actually evaporate.

In combination with your location and its humidity, it’s wise to think about how much you tend to sweat in general, as well

Additionally, there can be some debate between wearing a base layer and just wearing the least amount of clothing possible. This is also something that really depends on what makes you comfortable as a hiker.

Some will opt for a base layer, but make that base layer a swimsuit. That can be useful if you plan on stopping to swim along the way, but it may not always be the most comfortable otherwise.

Analyzing the Data

So only around 20% of people wear a long-sleeve base layer, while 35% said they prefer to wear as little as possible, while 43% said they wear shorts and a t-shirt. It’s clear that personal preference is the most important factor in what people wear in the summer.

Most of the time in hot summer conditions people aren’t wearing multiple layers, so their base layer is their only layer. The decision really is between going shirtless, long-sleeve, or short sleeve.

A light base layer can have a couple of added benefits on top of wicking sweat. Depending on how long you’re going to be hiking, you might want to at least bring along a base layer for the cooler hours of the day. In other situations, a long-sleeve base layer can be an excellent tool for keeping bugs away from your skin.

Comfort tends to be among the highest priorities when it comes to camping, hiking, or backpacking at any temperature. Heat can be difficult to escape, so making sure you’re as cool as possible is key to surviving and enjoying your time in the outdoors.

Overall, a base layer is a great idea. However, the choice is ultimately up to you. Some hikers aren’t a fan of the idea of wearing the extra coverage when they are trying to stay cool. Whatever you choose, don’t forget to bring along sunscreen. The protection sunscreen offers to your skin is valuable for any skin that is exposed to the sun.

Which Material Is Best For A Hot Weather Base Layer?

If you’re going to wear a base layer in hot weather, you really don’t want something that is going to add to your temperature. It’s already going to be hot outside, so a heavier base layer isn’t really the ideal choice. Instead, choosing something that is light and breathable will allow you the highest level of comfort.

That said, just about any base layer can work decently in hot weather as long as you opt for the lightweight version. The most common base layers out there include wool, silk, synthetics, and cotton. Each material offers different benefits and drawbacks, making each suitable for a different situation.


There are many out there who might be wondering why they should wear a base layer rather than a simple cotton t-shirt. Cotton in general is breathable, but it also tends to soak up sweat (in a kind of obvious way, too). Rather than wicking the sweat away, cotton just soaks it up and becomes wet and stays wet. Many people don’t like that feeling.

If you’re only going to be out for a short while, or know that you’ll be hiking in conditions where sweat won’t be too much of an issue, you can absolutely choose to go with cotton. Otherwise, there are a lot of benefits to be gained from a performance base layer.


Another option that might sound great for summer is silk. Silk can work decently well in a wide variety of conditions. However, it’s not ideal when you know you’re going to be sweating a lot. While it’s capable of wicking away an acceptable amount of sweat, it isn’t particularly resistant to odors, but many people are okay with that because of the cooling nature of silk.

Check out our article on silk base layers here.

It is worth considering that silk can absorb sweat in a less noticeable way than cotton, but the material still has its limits. Consequently, silk is a better option for an easygoing hike rather than a more difficult journey.

Synthetics (Polyester etc.)

Sweat is gonna happen in hot weather, so synthetics and merino wool are considered the ideal base layer choices. Both options are quite good for wicking away sweat, though synthetics may begin to stink slightly sooner. As long as you go with lightweight options, either material will do a great job of regulating your temperature and keeping sweat at bay.

Synthetics are often an easier choice to understand. Just select the kind of synthetic you’re interested in and make sure to grab a lightweight option. Based on this PubMed study, synthetics are known to be quite comfortable.

Depending on the study you look at, both synthetics and wool score very well in the category of comfort. Consequently, both options are great choices for any temperature as long as you choose a weight that matches the temperatures you’re going to be in.

On the other hand, synthetic options may include both nylon and polyester. Between the two, polyester is a far better option for warm weather because it is known to be more breathable. In warm temperatures, breathability is key to making sure you aren’t adding extra heat to your body.


Wool can seem like a more complicated choice because of the different weights the material is available in. With six different available options, it can be difficult to tell which will be the most suitable for warm weather. Ultimately, any variety of merino wool at or below 19.5 microns can work well for warmer conditions. Essentially, the warmer it is outside, the lower you want the micron count to be.

According to this study from ScienceDirect, wool can be among the most comfortable choices when it comes to base layers. Just make sure you’re choosing the right weight for the situation. Often, people think of warmth when they are imagining wearing wool, but it’s actually a great material for cooling or warming you, depending on the situation you’re in.

Ideal Clothing Color

The material you wear can make a huge difference in whether you’re staying warm or trying to remain as cool as possible in the heat, but does the color of your clothing matter? There could be a variety of reasons why you might want to choose certain colors over others while out on a hike, no matter what the temperature is. To discover more about the ideal colors to wear while hiking, check out our article on the topic here.

Can You Wear A Base Layer On Its Own?

In many cases, base layers are designed to be exactly that – a base layer. What that means is that many base layers may work most efficiently when they are combined with outer layers.

That said, not many people want to layer up their clothes when they’re going to be hiking in high temperatures. In that situation, it’s perfectly okay to wear a base layer as your only layer.

In fact, it can be considered the next best thing to wearing no clothing at all when it comes to staying as cool and comfortable as possible. Opting for something that wicks away your sweat while also providing breathability is a great idea. These options are typically very light, so you won’t have much in the way of added weight on your trip.

On top of that, the lightness means you can choose to just bring your base layers along with you if you choose. Some hikers may prefer to wear minimal clothing throughout the day and change into base layers when the temperature begins to cool down.

If you are opting to wear just a base layer out on a hike, make sure no one will be able to see through your clothing. Finding out that other hikers can see right through your outfit could be quite embarrassing, to say the least. Test out any base layers you might want to wear alone to ensure they won’t give you away in the sunlight on a hot day.

Speaking of keeping your body covered, how do you know if you need to wear underwear beneath thermals or a base layer? After all, they do seem an awful lot like underwear themselves, don’t they? Well, don’t worry. In our article on the topic, we’ll answer this question for you so that you can avoid the embarrassment of having to ask someone. Take a look at it here.


Peter is a software developer who loves to take every opportunity to go outside that he can get. Peter grew up going on long backpacking excursions with his family every Summer and now enjoys staying at the beautiful Texas State Parks and swimming in the amazing Texas Rivers.

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