Clema vs ThermApparel: Which Cooling Vest to Buy

At a glance

Side by side.

	ThermApparel UnderCool	Clema
How long it cools	1 to 3 hours	A full workday
To use it again	Put the packs back in a freezer	Swap the battery, keep working
Weight	About 1.3 to 1.9 lbs	Under 3 lbs
Needs charging	No	Yes
Works in humidity	Yes	Yes
Best for	A couple of hot hours	People who are hot all day

Pick ThermApparel if…

Short bursts of heat, and a freezer nearby.

We are not going to talk you out of a good product. The UnderCool is light, it disappears under a shirt, there is nothing to charge, and it costs far less than anything with a battery in it. For a couple of hot hours at a time it is very likely the right buy.

YesPeople are hot for an hour or two, not all day.
YesThere is a freezer they can actually get to.
YesYou want the lightest thing possible.
YesYou would rather not deal with batteries.

Pick Clema if…

You want it to last, without the downtime.

Every frozen-pack vest runs out. When it does, someone has to stop, find a freezer, and wait. That is fine at home and a real problem at work. Clema makes cold while you wear it, so it keeps going for a full day and a battery swap takes under a minute. Here is how that works, in plain English.

YesPeople are hot all day, not in short bursts.
YesStopping to refreeze packs is not realistic.
YesThere is no freezer on site, or none to spare.
YesYou want cooling that does not fade as the day goes on.

FAQ

Quick answers.

How long does a ThermApparel vest last?

ThermApparel publishes about 1 to 2 hours for its SlimCool packs and about 2 to 3 hours for its ExtendedCool packs. After that the packs have to go back in a freezer before they cool again. That is plenty for a commute, an errand, or a short stretch of heat. It is not a full workday.

Which one should I buy?

Ask how long your people are actually hot. If it is a couple of hours and there is a freezer nearby, ThermApparel is lighter, cheaper, and the sensible choice. If people are hot all day and stopping to swap frozen packs is not realistic, you want something that keeps cooling without a break, which is what Clema is built to do.

Do either of them stop working in humidity?

No. Both keep working when it is humid. Only evaporative vests, the kind you soak in water, fade in humid air. So humidity is not what separates these two. Cooling time is.

Still deciding? The cooling vest comparison covers every type, how long a cooling vest lasts has the timings side by side, and fit and sizing covers the thing that decides whether people actually wear it.

Related guides

Keep reading.

Full Comparison

Where does each type give out?

How Clema Works

Where does the heat actually go?

Fit & Sizing

Why does a loose vest cool less?

Clema vs ThermApparel