How to Wear an Undershirt in Hot Weather

We’ll explain why it’s a good idea to wear an undershirt in the summer if you wish to keep cool and avoid those irritating sweat stains on your top shirt.

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Picture this: It’s a sweltering summer day, you’re dressed in your sharpest suit for a crucial meeting, and as you step outside… BAM!

You’re hit with a wave of heat that makes you feel like you’ve just walked into a sauna.

Sound familiar?

If you’ve ever battled the dreaded pit stains or felt like you’re melting under your clothes, you’re not alone.

But here’s the kicker: wearing the right undershirt can be your secret weapon against summer sweat.

In this post, I’m going to show you exactly how to choose and wear undershirts that’ll keep you cool, dry, and confident – even when the mercury’s rising.

Let’s dive in!

Why Wear an Undershirt?

You might think that adding an extra layer would make you hotter. But here’s where it gets interesting.

A well-chosen undershirt can actually help regulate your body temperature and reduce visible sweat. Here’s why:

  • It acts as a barrier, absorbing sweat before it reaches your outer shirt
  • It helps wick moisture away from your skin, keeping you feeling dry
  • It can prevent embarrassing sweat stains on your visible clothing

But not all undershirts are created equal. Let’s break down what you need to look for.

What to Look For

When shopping for the perfect summer undershirt, keep these key factors in mind:

  • Breathable Fabric: Look for materials like TENCEL™ or micro modal that allow air to circulate.
  • Moisture-Wicking: The fabric should pull sweat away from your skin.
  • Slim Fit: Avoid baggy undershirts that bunch up under your clothes.
  • Proper Neckline: Choose a neckline that won’t peek out from under your shirt.
  • Comfort Details: Tagless designs and soft fabrics make a big difference.

Wearing a Dress Shirt in the Summer

There will come a time when you’re going to have to wear a dress shirt in the summer. In fact, you might be faced with this challenge every single weekday. It doesn’t have to be so daunting, though. And again, when you’ve got one of the best breathable undershirts in your corner (and on your body), it gets all that much easier.

First off, there are stretch dress shirts out there made with lightweight, more breathable fabric – modern, not stuffy. The same certainly goes for your undershirt.

Beneath a button-up where you’re going to have the collar undone a button or two, pay attention to the neckline of your undershirt: Your undershirt shouldn’t show when your shirt is unbuttoned.

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Long story short: If you’ve been worried about wearing an undershirt beneath a button down because your old undershirt peeks above the unbuttoned collar, worry no more: A V-neck undershirt solves that problem better than a regular T-shirt would.

Short sleeve undershirts should be your ultimate focus, too – no need to worry about a long-sleeve undershirt peeking its way beneath your shirt cuff.

Fit is also crucial here. Your dress shirt should be tailored to begin with, but not overly tight. Consider the same approach in terms of the fit of your undershirt. Go with a slim-fitting undershirt, the kind that won’t prove too baggy or visible beneath your dress shirt.

There’s still a time and a place for a crew neck undershirt, though. If your dress shirt is buttoned to the neck and you’re wearing a tie, a crewneck style of undershirt still works well.

Keep in mind that all the while, an undershirt’s soft fabric and moisture-wicking qualities are going to help you wear your dress shirt (and suit, and tie) with confidence.

Should I Wear An Undershirt With My Suit?

Wearing an Undershirt Under a Polo

Your summer wardrobe is all about variety and versatility – you’re not going to find yourself wearing a dress shirt 24/7 (or at least, we hope not).

You’ve more than likely got a favorite polo you turn towards when a sunny day dawns, but that begs the question: Can you wear an undershirt with a polo?

The answer is complicated, or at least, somewhat complicated. Wearing an undershirt beneath a short-sleeve polo is ultimately up to you.

Moisture-wicking polos made from lightweight stretch material are growing in popularity, especially polos that forgo traditional athletic logos (think of a dressy polo you could even wear to the office versus a polo you’d wear to the golf course).

As far as positives are concerned, V-neck undershirts provide another layer of moisture-wicking, absorbent capabilities in the heat. Short-sleeve undershirts are also a natural move to wear with a polo, provided the sleeves of your undershirt don’t peek through your polo.

You might be tempted in this case to wear a tank top, but extra underarm coverage and absorption can actually help fight sweat, so a deep V-neck might be the better bet here. Now, there are in fact some drawbacks to wearing an undershirt beneath a polo.

For one, if your polo itself is lightweight and moisture-wicking to begin with, you might not need an undershirt as readily as you would with a slightly heavier dress shirt.

And if your polo has an unusual button placket or slightly shorter sleeves, your undershirt might be somewhat visible through the polo. When in doubt, use a V-neck or deep V-neck undershirt with a polo, but consider forgoing the undershirt if your polo is made from a more tech-focused, stretchy material.

Best Undershirt Fabrics to Beat the Heat

It should be clear by now that shopping for an undershirt comes down to fit and fabric, right? Fabric is perhaps the most important part of the equation, since it’s going to be the layer closest to your skin.

In decades past, you probably grew used to wearing a cotton undershirt: For a time, it was the most common fabric for T-shirts, and everywhere you looked, you saw cotton undershirts. Fabrics have evolved with science over time, though.

Semi-synthetic fabrics like rayon (more commonly seen in things like the classic, breezy Hawaiian shirt) have made their way into the market, too. Semi-synthetic fibers aren’t natural, like 100 percent organic cotton. Organic cotton can be slubby and textured at times, but it’s often smooth when used in undershirts and T-shirts.

Semi-synthetic fibers tend to draw from both traditional and organic cotton, with a few added touches. That extra dose of science tends to make semi-synthetic fibers softer, smoother and lighter – plus more moisture-wicking – than fabrics like cotton. Granted, organic cotton is also mighty soft (and of course, all-natural).

TENCEL™ is also a notable semi-synthetic fiber (one that we love at UnderFit). It blends modal, a bio-based fabric made from cellulose, with lycra for a smooth, lightweight and stretchy feel against your skin – all better to target underarm sweat.

If you’re looking for extreme breathability, a semi-synthetic fiber, like something made with modal fabric, is going to stack up better than a slightly heavier fiber than cotton or organic cotton. Of course, an undershirt in its own right is going to help in the battle against perspiration in general.

Frequently Asked Questions

Does Wearing an Undershirt Keep You Cooler?

Yes. Wearing an undershirt made from a breathable, moisture absorbing material will keep you cooler in hot weather. It works because the fabric pulls moisture from your body, which keeps you dry and comfortable. We’ve found that our TENCEL™ fabric blend is the perfect combination of fabric for hot and cool weather.

Should You Wear an Undershirt in the Summer?

An undershirt will keep you cooler in hot weather and humid climates, while also absorbing sweat and preventing it from soaking your outer clothes – whether it’s your favorite dress shirt or polo.

Worried About Staying Fresh And Beating the Heat? Don’t Sweat It

There are lots of factors to keep in mind when wearing an undershirt. As long as you’re focused on fabric and fit – and choosing the best undershirt for your outfit – you’re already ahead on the leaderboard. Stay cool out there.

Leigh is the owner of UnderFit, a premium men's undershirt brand based in Philadelphia, PA. You can follow Leigh on LinkedIn and Twitter.

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