Baselayer T-Shirts

FR Baselayer T-Shirts Built to Wear Under Your Gear 

Most FR shirts are built to be the outermost layer — this one's built to go underneath. Our FR baselayer t-shirts are designed specifically to sit under your other flame resistant gear, giving you a moisture-wicking, flame resistant base that keeps you dry and protected without adding bulk. At 5.5oz with a 60% Modacrylic Blendmix Spandex construction, these tees stretch with your movement instead of bunching up under a jacket or coverall.

The modacrylic blend is what sets a baselayer apart from a regular FR tee. It's softer against the skin, lighter in weight, and pulls moisture away from the body — which matters a lot when you're wearing multiple FR layers on a hot job site. That blend is also inherently flame resistant, meaning the protection doesn't wash out over time the way treated fabrics can.

Why workers use an FR baselayer:

A lot of guys skip the baselayer and go straight to their FR shirt — until they've had a few long shifts in heavy gear and figure out why layering smart matters. An FR baselayer keeps sweat off the skin, which actually helps with temperature regulation whether it's hot or cold outside. In cold weather, it adds a thin warm layer without the stiffness of a thicker shirt. In summer, it manages moisture so the rest of your gear stays more comfortable.

These baselayer tees come in grey, navy, and khaki — neutral enough to wear under whatever you've got on top without showing through. They work well under any of the heavier shirts in our lineup, and they're light enough that you won't notice them once they're on.

If you're building a full FR layering system, this is the piece that goes on first. For what goes on top, our FR Shirts for Men collection covers every style — snap shirts, button downs, crewnecks, and more. For outerwear on top of that, our FR Hoodies for Men and FR Jackets for Men round out the stack. And if you want to see everything we carry in one place, the FR Clothing collection has the full picture.

Browse the complete range of FR and hi-vis gear at the NKE Safety Apparel. Orders over $99 ship free, and if you've got questions about fit or fabric, reach out through the Contact Us page.

Frequently Asked Questions

1. What's an FR baselayer t-shirt and how is it different from a regular FR tee? 

A regular FR t-shirt is built to wear on its own. A baselayer is built to go underneath — it's lighter, stretchier, and designed to wick moisture away from the skin so the rest of your FR layers stay more comfortable. This one uses a 60% Modacrylic Blendmix Spandex fabric, which is softer and more flexible than the 100% cotton used in most standard FR tees.

2. Can I wear this baselayer tee on its own or only under other gear? 

You can wear it on its own, but it's purpose-built for layering. If you're working a hot shift and need something light, it'll work — but most guys wear it under a heavier FR shirt or jacket as a first layer.

3. What fabric is used in the FR baselayer t-shirts? 

5.5oz, 60% Modacrylic Blendmix Spandex. The modacrylic is inherently flame resistant — protection is in the fiber, not a surface treatment — and the spandex adds stretch so it moves with you under other gear.

4. Does the flame resistant protection wash out on a modacrylic blend shirt? 

No, that's one of the main advantages of modacrylic fabric. Because the FR properties are built into the fiber itself, they don't degrade with repeated washing the way chemical-treated fabrics can. Standard care instructions apply — avoid bleach and fabric softener, wash in cold or warm water, tumble dry low.

5. What colors does the FR baselayer t-shirt come in? 

Grey, navy, and khaki. All neutral enough to work under whatever you're wearing on top.

6. Does this baselayer work in both hot and cold weather? 

Yes. In cold weather, it adds a thin warm layer that doesn't bulk up under your FR shirt or jacket. In hot weather, the moisture-wicking fabric helps keep sweat off the skin so the rest of your gear stays more bearable.

7. Do you offer free shipping on FR baselayer t-shirts? 

Yep, $99 and up ships free within the US. You can mix this with anything else across NKE Safety Apparel to hit that.