Do cooling vest work?

Stick some ice down your shirt, pockets, crack, dick and hat. At any water source get very wet and stay wet.

Yep! We used them before cross races in college if it was a burner. The effects were obviously minimal because we'd be racing within minutes and raising core temp back up, but it kept HR low and kept you calm before the effort.

Have never run in them but would agree that if you can get wet and stay wet *pause* then you should

Your core will rapidly overcome the capacity of a vest if worn while running on a hot day, so bear that in mind. then you're stuck with a vest having no effect. as we know they are used extensively by pros in warmups before a race to fight off temperature rise while elevating their heart rate to be ready for the gun while not quite as hot as of they hadnt used the vest.

As for what works on actual runs, the ice cube in your buttcrack thing does actually work to signal/trick your body into thinking it is cooler than it is for a period of time. that may work in the case of a short race.

For longer duration, ice under the cap is the most practical, impactful and sustainable over a long period of time. if its loose it has the effect of dripping the cool water which is huge, but if you flatten it into a ziplock bag you can get like 40-45 minutes of ice, and its still cooler than your head once its completely melted. Galen Rupp used this method on repeat during the previous olympic marathon trials to great effect.

Trick is to find a deeper hat that would normally ride quite low on you so it can ride normally filled with ice.

The science is sound on ice vests. Use them pre-run/workout/race. You don't want to run with one on. Ok to stick ice in a hat or in other places. There are also cooling headbands like Omius, which have become increasingly popular in triathlon, that haven't quite made their way onto the running scene.

On warm days, an ice vest will held lower your heart rate and lower your core body temperature. If it's really gross out, you can really only delay the effects for so long but why start already disadvantaged.

sheeeeeeesh $209 for a cap.

Any idea why they haven't made their way onto the running scene if they actually work?

I've had heat exhaustion before so I'm more susceptible to problems with heat.

There's a (relatively) new material that has a significant cooling effect if worn as arm sleeves. On Temu, it's called ice silk and it's dirt cheap. I used them last summer. You wet them and then the evaporation has a very noticeable cooling effect. It's not a miracle worker. It lowers the feels-like temperature on your arms about 10 degrees and the overall effect is maybe 3 degrees. I wore them last summer at the USATF Masters Championships in North Carolina. They definitely helped, but after two days, I was too sick just from being outside in the heat to stay until the end of the meet.

I've also tried the ice silk shirts, shorts, underwear and caps. The shirts are marginally better than a regular summer running top. The shorts, underwear, and cap are marginally better for walking around in the heat, but I they don't seem to provide me a benefit when working out.

Oh, if you buy ice silk arm sleeves from Temu, only buy the plus size. The regular size is tiny. I have 14 1/2" biceps (not that big, but just giving a reference point) and the regular size is uncomfortably tight. They're cheap... maybe $3 a pair for the plus size.