If you're wearing the wrong hi-vis on the wrong July day, you're going to feel it by 11 AM. There's a real, measurable temperature gap between solid-fabric Class 2 polyester and ventilated mesh Class 2, and on an asphalt site, that gap is the difference between functional and miserable.
The cheapest hi-vis we stock is a $14 polyester Class 2 t-shirt — generic, no brand worth mentioning, sells fine in October but a roaster in July. We don't pretend otherwise. If a guy comes in for a $14 hi-vis in July, we tell him: it'll get you through a half-day, but you're going to wish you'd spent more by lunch.
Step up: Carhartt Force High-Vis Color-Block Class 2 t-shirt at $30. Better fabric, sweat-wicking, holds reflective tape through 30+ washes. This is our best-selling summer hi-vis. The Force fabric is the difference.
Step up again: Carhartt Force Sun Defender Lightweight Long-Sleeve Hi-Vis at $40. UPF 50, mesh ventilation panels under the arms and across the back, long-sleeve so you're not getting forearm-burned through the day. This is what most experienced outdoor crews end up in by their second summer.
For vests, the Carhartt High-Vis Class 2 Mesh Vest at $35 is the floor. The full-mesh Ergodyne Glowear 8210Z at $30 is a similar option. Either is light-years better than a solid-poly vest in heat.
If you're in flag-traffic or right-of-way work and you need Class 3, the long-sleeve hi-vis t-shirts handle it as long as the reflective tape configuration is right. Verify with your foreman, not with us. We don't certify.
One thing about reflective tape and washing. Cheap reflective tape (the silver-gray strips) starts to peel and crack after 15 to 20 washes on the cheap shirts. The Carhartt Force tape is heat-applied differently and survives 50+ washes. Over a season of daily wear and a wash every two days, that's the difference between buying one good shirt or three cheap ones.
Last note. If your foreman lets you choose your own hi-vis, pick the lightest, most ventilated thing that meets the class requirement. Hi-vis isn't supposed to be the warmest layer in your kit. In July, it's supposed to be barely there.