From hot honey to chili chocolate... Spicy is always in style.

So what fuels our fiery obsession and how do our bodies respond to the burn?

First things first.

What makes hot peppers so spicy?

The culprit is capsaicin, a compound found in chili peppers that is responsible for the burning sensation.

Think of capsaicin as the fiery bodyguard of the pepper warding off invaders with its heat.

It helps plants defend themselves from predators.

And we have evidence that it can also protect seeds from fungus and other pathogens.

Producing capsaicin requires a lot of energy, so plants may not bear as many fruits as plants that don't use this kind of defense.

Now there are a lot of different kinds of peppers ranging in the degree to which they...well...burn.

Some experts claim that the thinner the stem, the hotter the pepper.

Many of these fruits get spicier as they age.

You can also think of dried peppers as a dehydrated spice bomb.

They have a higher capsaicin concentration than fresh peppers because the water has evaporated.

We often use the Scoville scale to measure a pepper's hotness, thanks to Wilbur Scoville, an early 20th century pharmacist.

The Scoville scale classifies heat as a series of units ranging from 0 to 16 million, which is the value of pure capsaicin.

The wide spectrum of peppers varies tremendously from the bell pepper, with zero heat units to the dragon's breath pepper, which reaches an impressive 2.48 million units!

I think I won't be trying that one.

So what does capsaicin do to our bodies?

Generally speaking, capsaicin is an irritant.

It binds to nerve receptors along the gastrointestinal tract that can be triggered by heat, including in our mouths.

When activated, they send powerful pain signals to our brain in ways similar to encountering an actual fire.

Our bodies interpret this information as if the temperature has risen, telling us it's time to cool off and that's one reason hot peppers can make us flushed and sweaty.

It is also possible to build up a tolerance to spicy foods.

Over time, our mouth's pain receptors can become desensitized with repeated exposure to capsaicin, allowing us to eat hotter and hotter foods.

But we don't all experience capsaicin the same way.

A person without a tolerance for hot peppers will feel more than a burning sensation, and they experience an inflammatory reaction.

Their throat can swell, making them short of breath.

They might have an upset stomach or feel nauseous as the body attempts to get rid of the culprit.

So is it possible for spicy foods to have a positive effect?

There has been some speculative research suggesting that eating spicy foods might increase metabolism or lead to a healthier heart.

What we do know is that capsaicin can be used as a pain reliever.

Applied as a patch or cream, it can treat sore muscles, arthritis and even shingles.

Returning to capsaicin in our food, let's explore the best way to extinguish the burn of a hot pepper.

Most of us know we need to drink milk, not water.

But why?

To keep it simple, water is what's called a polar molecule because each side has a partial negative or partial positive charge.

The capsaicin in peppers is non-polar, so each side balances the other out As chemists might say, "Like dissolves like."

So if you feel your mouth on fire and you reach for water, the pain can actually feel worse because the capsaicin is not dissolved but spreads around your mouth.

Instead, that milk or maybe ice cream or even cottage cheese contains another non-polar molecule called Casein which encircles the capsaicin molecules and washes them away.

Like dissolves like.

Now that we have covered some of the science of spice, let's meet three very brave taste testers.

I could just eat plain cracker.

Feels like fire.

No reaction.

Let's start with the chip.

And on a scale of 1 to 10, tell me how spicy it tastes to you.

Zero out of ten.

It's not spicy at all.

Summer, what did you think?

Umm...Maybe like a one out of ten.

And Violet looks like she's not feeling anything at all.

Let's move on to the cheese.

It tastes like normal cheese.

I can, like, taste the peppers, but the peppers aren't spicy.

They just taste bad.

And Atlas?

It's still not spicy.

Okay.

I actually tried that cheese, and it is super spicy.

Now we're going to try the habanero.

Looks like Violet isn't a fan.

Violet, was that a lot hotter?

Yeah.

It wasn't spicy!

Tastes like a spicy bell pepper.

Oh, okay.

It's, like, really spicy.

I took, like, a whole... Can I see you take one more?

Okay.

It's not spicy.

I feel like everywhere it touched, it kind of like just burns a little bit.

It wasn't spicy!

For the habanero... <coughing> What does it feel like in your mouth?

It... feels... like... fire.

<laughing> Just a tiny bit of spiciness on my lips.

On your lips?

Yeah.

Just a tiny bit of spiciness on my lips.

Well, I feel like I should try something, too.

So let's see.

It's not that hot.

Oooh...no!

Yes it is!

Thanks for sharing your sharing your milk.

It is spicy!