Base layer vs thermal debate can cause a few questions. The are in essence on in the same. Thermals come under the category of base layers. They are a type of base layer. However many people use the term interchangeably which is absolutely fine. The reason for this is because thermal base layers are the most common type of base layer.
So when you think about base layer vs thermal just remember they are mostly the same thing but there are actually many types of base layers but thermals being the king of them all.
Base Layer vs Thermal
Let’s have a look at each of the two parties in this base layer vs thermal debate. From these descriptions and analysis you will be able to see the similarities. You will also learn why they are both important for you and your family especially if you love the outdoors.
Base Layers
A base layer is the first layer of clothing that is closest to your body. It’s main purpose is to regulate your body temperature. This will mean either keeping your body warm or cooling it down.
An additional purpose of a base layer is to wick away moisture from the skin in order to keep you as dry as possible. Wicking means that the material absorbs and moisture present on the skin. This will keep you dry and prevent you from becoming uncomfortable and help in temperature regulation.
Base layers are particularly important in winter when it comes to children, especially young children. The younger a child the more difficult it is for their little bodies to regulate their own temperature. This becomes even more difficult in winter. Be sure to read this post on how to dress your child correctly during the winter months.
Thermal Layers
Thermal layers are a type of base layer. There are many different base layers but thermals are probably the most recognised. When you are thinking about base layer vs thermal there really isn’t too much difference.
A thermal layer has all the desired qualities for keep you either warm or cool. They are actually really fascinating because the same item of clothing can perform two opposite functions depending on the need of the wearer. In winter the are great insulators and in summer they work great at keeping a consistent temperature while the sun bears down on you. I am sure there is some incredible science there that I don’t quite understand but can appreciate nonetheless.
Thermal layers are brilliant because they trap heat and keep it nice at close to your skin in winter. During high school our winter uniform consisted of a white blouse and a long kilt (yes the kilt was incredibly impractical but they have finally changed it) Now, I can assure you that without thermals underneath my uniform I would have spent the entire day freezing my rear end off. Thermals made a very ill thought out uniform all that more bearable and actually quite warm.
Why You Need Thermal Base Layers
You need to have a thermal base layer, particularly in winter because it is going to stop you being cold. It is that simple. No one likes to be cold and this is one of the best ways to avoid it outside of carrying your blankets around town with you!
A thermal base layer is going to your first defence against the cold. It is also going to be your most effective defence.
In the summer months thermal layers are excellent for keeping you cool. Their ability that wick away, or absorb moisture is what keeps you cooler. All that sweat that was sitting on your skin heating you up is now absorbed into the material away from your body.
The Best Material For Base Layers
The best material for base layers is merino wool. Merino wool is quite different to regular wool in that its fibre structure is much finer. This means it is incredibly comfortable to wear and doesn’t scratch.
Merino wool has the astounding ability to absorb 35% of its own weight in moisture. That is incredible. I am not sure any one is going to sweat enough to out do that. Also in winter that is a decent amount of ice or rain that it can protect you from. If the rain or snow manages to penetrate through your other outer layers it is really not going to stand much of a chance getting through your merino base layer.
Merino is an active fibre. Which means it is pretty smart. It can tune into what the wearers body is saying and either hold in all the heat to keep you warm or release it all and keep you cool. I have always had merino sleep sacks for my kids and could be reassured they would stay at a comfortable temperature all night long. This meant more sleep for me too!
Another really great quality of merino wool is that it is flame resistant. This is so important to me as a mother because you really never can trust kids around a fire. All it takes is one misstep and they can get into serious trouble. One of my biggest fears with my children getting burnt is that they fabric will melt and stick to their little bodies. Merino wool does not melt and it will not stick.
Why You Need To Avoid Cotton
Cotton is a commonly thought of as a superior fabric. It most cases this is 100% true. However when it comes to base layers and in particular thermal base layers is it one of the worst performers.
It does the complete opposite of what you want a base layer to do. It soaks up all the moisture but it can’t absorb it appropriately leaving it wet. After it has become wet and soggy it also struggles immensly to be keep the wearer warm because instead of trapping the heat next to the body it instead draws it away from the body.
Think about wearing a cotton t-shirt in the rain. Once that t-shirt is wet, it is wet. None of the water is absorbs and the t-shirt stays wet against the skin until the sun starts shining and it dries or your body temperature dries it out. In any case you are likely going to be wet and miserable. It also becomes heavy and sticky which make you feel even more desperate to find warmth.
The only time to use cotton base layers is if it is just mild weather. We live in a tropical type environment where is it pretty nice t-shirt weather year round. However there are days when it is rather chilly in the mornings and at night. In these circumstances I have no problem having my children wear cheap cotton base layers. Once we head to the snow, or countries with much colder climates I make sure I have merino base layers for everyone.
How To Wear Thermals
Thermals need to be worn snug and tight to the skin for optimal performance. They are not intended to be baggy but to act as a second skin almost.
Thermal Tops
A thermal top is the most common item of thermal wear. Wearing a thermal top, especially on outdoor adventures is a must. Think about your activity for the day and how hard you will be working and the weather on the day. I find it best to invest in both a short sleeve and long sleeve base layer just so you have options. If you are going to be doing strenuous activity or it’s mild weather a short sleeve thermal will be fine. For colder temperatures opt for a long sleeve. This advice goes the same for kids too. Always dress them in layers that are easy to remove or add as the day goes on.
Thermal Bottoms
I generally only wear thermal bottoms when it’s winter. In summer compression active wear is usually my pick for bottoms. This goes for my kids too once they reach 8 or so. My younger kids will wear long tight fitting pants to hike because of ticks and poisonous plants. Or if we are just adventuring other places shorts are fine in summer.
Thermal bottoms are like little bursts of happiness in winter because you can wear them under jeans, dresses, pants, snow pants, you name it you can probably put thermals under it in winter. I actually really love wearing thermal bottoms to sleep in.
Thermal Accessories
You can also invest in thermal base layer accessories such as hats, gloves, balaclavas and socks. If you add all these accessories to your base layer kit you and your kids are going to be as snug as bugs come winter. It is actually very important to keep your head, feet and hands warm as this is where you lose a lot of heat. Have you ever noticed that if you are in bed and your feet a cold your whole body feels cold. It is almost impossible to sleep when you have cold feet.
When You Should Wear Thermals
Thermal base layers can be worn year round. I think they are most vital in winter months because they are one of the best ways to keep you warm and dry in less that ideal weather.
I hesitate to give a specific temperature for when you should start wearing them for the winter season it really goes on personal preferecnce. Once you start feeling too cold in your regular clothes it is probably time to add that extra base layer. This goes for kids too.
What my family feels is cold will be far different to what someone from Alaska might think is cold. Just for reference once it hits 18C/65F I am thinking about turning on the heating! I just looked and in the middle of summer in Alaska sometimes that’s the high! So with that said use your own judgement.
In summer thermal layers are good for every day wear. There are great options that don’t look like undergarments that you can wear as a single layer with perhaps a second layer in your pack just incase you need it. We really only wear thermal tops in winter for hiking. The rest of summer is just t-shirts and shorts. Base layers in summer really come down to the activity. It gets up to 45c/115F during the summer here so at that point we are either in the water on in the air conditioning!
