Clema Technology. How Active Cooling Works

Q: How does an active cooling vest work?

An active cooling vest works more like a refrigerator than a cooler. A cooler stays cold only until its ice melts; a refrigerator keeps removing heat continuously as long as it has power. Clema is solid-state and battery-powered, so instead of slowly thawing like ice or gel packs, it pulls heat off the body continuously through the shift.

Q: What is solid-state active cooling?

Solid-state active cooling cools using electricity rather than melting ice, evaporating water, or circulating refrigerant. Because nothing is stored that can run out and there is nothing to refill, it delivers steady, repeatable cooling on demand, the way any electric appliance runs consistently whenever it is powered.

Q: How is active cooling different from ice, PCM, and evaporative vests?

Ice and PCM vests hold a fixed amount of cooling and fade as they warm up. Evaporative vests depend on dry air and lose effectiveness in humidity. Active cooling is powered, so it stays consistent from the first minute to the last and performs the same in dry or humid heat. Think continuous air conditioning versus a bag of ice.

Q: Does Clema use ice, gel packs, or water?

No. Clema uses no consumable cooling medium, nothing to freeze, soak, or refill. The cooling is powered electrically and runs on a hot-swappable battery, so a crew resets for the next shift by swapping a battery rather than restocking a freezer.

Q: Does an active cooling vest work in high humidity?

Yes. Because Clema does not rely on evaporation, humidity does not reduce its performance. It delivers the same cooling in humid heat as in dry heat, a key advantage over evaporative vests, which weaken as humidity rises.

Q: How bulky is Clema to wear?

Clema is lightweight (under 3 lbs) and built as a low-profile suspender system that works with a fall-arrest harness, so cooling stays out of the way of the gear a crew already wears.

Q: Is Clema a wearable cooling device or a personal cooling system?

Both terms describe it accurately. Clema is a wearable cooling device, and specifically a personal cooling system: battery-powered wearable technology that regulates body temperature independent of ambient conditions. It fits the broader category of industrial wearables and connected worker technology, PPE built to actively manage a worker's physical state through a shift, not just protect against a hazard passively.

The core idea

Every other vest stores cold. Clema makes it.

Passive vests

Hold a finite cooling reserve, fixed the moment you put them on, and fade as the shift wears on.

Clema

Pulls heat off the body on demand, and dials up or down at the push of a button. Steady from clock-in to clock-out.

Cooling delivered · full shift Clema Passive ice / gel

The dip is a sub-minute battery swap. Cooling barely pauses. Passive vests just fade.

How it works

Powered cooling, explained simply.

Clema’s active cooling wearable uses battery-powered thermoelectric (Peltier) modules in direct contact with the skin. Electricity allows each module to transfer heat from its cold side, against the skin, to its hot side. That heat must then leave the device for cooling to continue. A fan moves air through a thin, flexible duct around the modules, carrying heat away through an outlet. The fan handles heat removal from the modules; the modules provide the contact cooling. This air-cooled system does not require ice packs, water circulation, or refilling.

Removes heat

Pulls heat off the body electrically, on demand.

Dial it up or down

Turn it up when heat spikes, ease off when it drops.

Full-shift power

4–6 hrs a charge. One swap covers a full shift.

Works in humidity

Same cooling in humid air as in dry heat.

Nothing to refill

No ice, no water, no freezer to find.

How it wears

Lightweight, powered, out of the way.

Cooling that disappears under the gear and lasts a full shift.

Low profile

Sits flat under hi-vis and a fall-arrest harness.

No mods

Zero changes to your gear.

Under 3 lbs

Barely there all shift.

Hot-swap

Fresh battery in under a minute.

Specs

Clema at a glance.

8–12 hr

Full shift, one battery swap

>25°F

Felt temp drop

<3 lbs

Worn weight

120°F+

Rated environment

<1 min

Battery hot-swap

Zero

Ice, water, or gels

Works in any humidity. Under 3 lbs, and it works with a fall-arrest harness.

FAQ

Clema technology: short answers.

How does an active cooling vest work?

An active cooling vest works more like a refrigerator than a cooler. A cooler stays cold only until its ice melts; a refrigerator keeps removing heat continuously as long as it has power. Clema is solid-state and battery-powered, so instead of slowly thawing like ice or gel packs, it pulls heat off the body continuously through the shift.

What is solid-state active cooling?

Solid-state active cooling cools using electricity rather than melting ice, evaporating water, or circulating refrigerant. Because nothing is stored that can run out and there's nothing to refill, it delivers steady, repeatable cooling on demand, the way any electric appliance runs consistently whenever it's powered.

How is active cooling different from ice, PCM, and evaporative vests?

Ice and PCM vests hold a fixed amount of cooling and fade as they warm up. Evaporative vests depend on dry air and lose effectiveness in humidity. Active cooling is powered, so it stays consistent from the first minute to the last and performs the same in dry or humid heat. Think continuous air conditioning versus a bag of ice.

Does Clema use ice, gel packs, or water?

No. Clema uses no consumable cooling medium, nothing to freeze, soak, or refill. The cooling is powered electrically and runs on a hot-swappable battery, so a crew resets for the next shift by swapping a battery rather than restocking a freezer.

Does an active cooling vest work in high humidity?

Yes. Because Clema doesn't rely on evaporation, humidity doesn't reduce its performance. It delivers the same cooling in humid heat as in dry heat, a key advantage over evaporative vests, which weaken as humidity rises.

How bulky is Clema to wear?

Clema is lightweight (under 3 lbs) and built as a low-profile suspender system that works with a fall-arrest harness, so cooling stays out of the way of the gear a crew already wears.

Is Clema a wearable cooling device or a personal cooling system?

Both terms describe it accurately. Clema is a wearable cooling device, and specifically a personal cooling system: battery-powered wearable technology that regulates body temperature independent of ambient conditions. It fits the broader category of industrial wearables and connected worker technology, PPE built to actively manage a worker's physical state through a shift, not just protect against a hazard passively.

Related guides

Keep reading.

Cooling Vest Types Compared

What makes active cooling different?

How Long Does a Cooling Vest Last?

Why do most quit before lunch?

Glossary

Ten terms worth knowing before you buy.

How Clema cools.