Cooling Vest for Women: Fit, Sizing, and Runtime

Where the problem actually is

The gear is the problem, not your physiology.

There is no separate women's heat-tolerance story to tell. When researchers tested whether sex changes how a body sheds heat, sex explained almost none of the difference. Body size and how hard you are working explained it.

What is different is the equipment. Work gear on most sites was specified for a workforce that is overwhelmingly male, and cooling vests inherited that default along with the boots and the harnesses.

4.3%

Of construction trades are women

Construction and extraction occupations, 2024. The gear was sized for the other 95.7% (CPS via IWPR, 2025).

Contact

Is what decides the cooling

Heat leaves you where the panel meets skin. An air gap cools nothing. That is physics, not preference.

73%

Of heat deaths hit in week one

Before the body has adjusted (Tustin et al., JOEM, 2018).

10 of 359

US heat deaths that were women

Occupational, 2000 to 2010. Heat follows the job (Gubernot et al., 2015).

Said plainly: heat kills more men at work because men hold nearly all of the jobs done in direct sun. That is a statement about who is standing in the heat, not about who tolerates it. The men's page covers that side.

The mechanism

Cooling is a contact sport.

Cross-section through the chest. A panel that follows the curve keeps every square inch in service. A rigid pack cut for a broader torso bridges the curve, touches at one point, and everything either side of that point has stopped cooling while the vest is still on and still running.

A flexible panel

Follows the curve.

Full width in contact, so every square inch is moving heat. This is what you are paying for.

A rigid pack

Bridges straight over it.

Touching at one point. Everything either side of it is an air gap, and an air gap cools nothing at all.

In contact, cooling Air gap, no transfer Body surface

What goes wrong

Three fit failures, and what each one costs.

Every one of these looks like a comfort issue and is actually lost surface area. Check all three with the vest on and your arms up, not standing still in a shop.

01

Chest gap

Rigid packs bridge across the chest instead of sitting on it. The vest is on. The cooling is not touching.

Costs the largest panel area

02

Shoulder slip

Straps set for broader shoulders slide outward, and the whole panel drops with them as the shift goes on.

Costs contact everywhere at once

03

Torso length

A vest cut long rides up off the lower back the first time you reach overhead, and it stays there.

Costs the lower back permanently

The test that settles it: slide a flat hand between the vest and your chest. Mild resistance is right. If you can pinch a fold of empty vest away from your body, that section has stopped working. Full version in the fit and sizing guide.

A woman in a hi-vis vest, hard hat and safety goggles standing in an industrial plant — The gear on most sites was specified for someone else's torso.

A woman on a construction site wearing a Clema cooling vest prototype against a base layer — Clema prototype worn against a base layer, panel flat to the torso.

A woman pulling a hi-vis vest on over a Clema cooling vest worn against a base layer — Cooling goes under the hi-vis, never over it.

How to compare

How do the types behave on a smaller frame?

Two questions decide it. Does it sit flat on your torso, and is it still working at the end of the shift. Most types fail one or the other.

Type	On a smaller torso	How long it lasts
Ice vest	Rigid packs bridge the chest, and add wet weight as they go	1–2 hr
Phase-change (PCM)	Same bridging, plus hours in a freezer between uses	2–3 hr
Evaporative	Stretches once soaked, so it fits differently wet than dry	Varies. Stops in humidity.
Fan vest	Needs an air gap by design, and carries bulk at the shoulders	Battery-limited
Solid-state (Clema)	Flat panel that adjusts across a wide range, nothing to load	8–12 hr

Deeper teardown: every vest type compared, how long each one really lasts, and what survives humidity.

Clema sizing

Two sizes, and no separate women's cut.

Straight answer, because the industry is usually vague about it: Clema does not make a women's version. It ships in two sizes and the same two serve everyone. What makes that work on a smaller frame is the panel, which is flat and adjusts across a wide range instead of being a rigid pack that has to bridge whatever is underneath it.

Size 1

Standard

Height: Under 6'1"
Weight: Under 220 lbs
Take it if: Both are true

Size 2

Large

Height: 6'1" and over
Weight: 220 lbs and over
Take it if: Either one is true

Most women take Standard. Over the line on either measure, take Large: a slightly larger panel that still sits flat cools better than a smaller one that pulls tight and gaps at the shoulders. Sizing a mixed crew? Send us the height and weight range and we will work out the split with you. Talk to the team.

FAQ

Straight answers.

Is there a cooling vest made specifically for women?

Very few. Almost every industrial cooling vest is sold unisex, which in practice means cut for an average male torso. Clema is straight about this: it ships in two sizes, Standard and Large, and the same two serve everyone. What makes it work on a smaller frame is that the cooling panel is flat and adjusts across a wide range rather than being a rigid pack that has to bridge the chest.

Do women need a different cooling vest than men?

Not physiologically. When researchers tested whether sex changes how a body sheds heat, sex explained almost none of the difference. Body size and workload explained it. What women do need is a vest that actually makes contact, because a vest cut for a broader torso gaps at the chest and slides at the shoulders, and cooling only transfers where the panel touches you.

What size Clema should a woman take?

Standard, in most cases. Take Standard if you are under 6'1" and under 220 lbs. Take Large if either one is over the line. The panel adjusts across a wide range, so the goal is a panel that sits flat against the torso rather than the smallest size you can close. Full method in the fit and sizing guide.

Can you wear a cooling vest under a hi-vis vest?

Yes, and that is the right order. The cooling vest goes against a thin base layer and the hi-vis goes over it. Cooling worn on the outside has to work through whatever is underneath, which wastes most of the effect. Slim vests also sit under a fall-arrest harness; bulky ice and fan vests get in the way of where the harness needs to sit.

Why does a loose cooling vest cool less?

Because cooling transfers by contact. An air gap between the panel and your skin is not cooling anything. A vest that gaps at the chest or rides up off the lower back has taken that surface area out of service, even though the vest is still on and still running.

How long does a cooling vest last on a full shift?

It depends entirely on the type. An ice vest fades in about one to two hours and phase-change packs run two to three before they need a freezer. Evaporative vests vary with the air and stop working in humidity. Solid-state cooling like Clema runs 8 to 12 hours on one battery swap because it makes cold rather than carrying a store of it. See how long each type lasts.

Cooling Vest for Women: Why Does Fit Decide the Cooling?