The average human sweats at least a liter of liquid every day. And depending on what you do (e.g. office work versus manual labor) and where you do it (e.g. Duluth, MN, versus San Antonio, TX), you could sweat a lot more — like several liters a day more. But regardless of these factors, sweating is something that everybody does. So here are some fun facts about the product of your pores.

A human body has between two million and four million sweat glands.
They’re really small, and we’ve got a lot of them. The output of each individual gland may be small, but when you have a few million of anything, the numbers can add up pretty quickly, no matter the individual workload.

Sweating cools you down through basic physics.
It’s not just the fact that your skin is wet that makes it cooler — it’s what that water does to your skin when it evaporates. Evaporation is what happens when water turns to a gas, and it requires heat. When your body temperature gets high, sweat glands cover your skin in a film of liquid so thin that the new heat from your skin is enough to evaporate the water. This process actually leaches heat from the skin, thus cooling it.

“Nervous sweating” is has evolutionary roots.
Why do we sweat when we’re nervous, if there’s no corresponding rise in body temperature? Your body’s “fight-or-flight” response evolved to prepare us to act in an emergency. When we sense danger, our body tries to preemptively cool us down in case we need to run. The trouble is, our modern brains interpret danger the same way primitive brains did: any uncertain situation. These days that can include first dates and job interviews, and even though our conscious mind knows these aren’t life-or-death situations, our unconscious mind only reacts to the uncertainty of the moment.

Some people sweat too much.
It’s a condition called “hyperhidrosis,” and it affects over eight million Americans. Sufferers can sweat four or five times more than the average person, with some areas (like the hands or the scalp) sweating far more than others. Unfortunately, the condition can exacerbate itself, since knowing you sweat excessively can make you nervous to be out in public, which in turn can make you sweat even more.

There’s a machine that can help you stop sweating.
Iontophoresis units can actually reduce the amount of sweat your body puts out, which can be one of the more effective hyperhidrosis treatments. An iontophoresis unit can help to shut down sweat-producing glands by administering an ionized material through the dermis. This method doesn’t break the skin at all, but rather uses differently charged conductors to transfer the ionized solution directly through the skin and to the glands, successfully treating hyperhidrosis in ten-to-twenty-minute sessions. Iontophoresis units are also being used to address certain vitamin deficiencies and to treat migraines.