Have you ever eaten a spicy dish, laden with hot chili peppers, and experienced an all-over warming sensation in your body? Perhaps you even felt overheated and begin to sweat. Maybe, this happens to you any time you eat hot peppers, or only when you eat an extremely hot variety or a large amount.
What causes this warming sensation? Is it different than the burning sensation in the mouth, lips, or on the skin (from chili pepper contact)?
The reason your body heats up when consuming chili peppers is owed to the same mechanisms that cause the burning sensation in your mouth. It is your body’s reaction to the capsaicin in chiles. As I explained in my look at why chili seeds aren’t actually hot, your taste buds cannot actually detect and register the capsaicin in chili peppers.
Instead, trigeminal cells, special pain detectors in your mouth, nose, and stomach, detect the capsaicin and react to it and detect it as “hotness,” causing them to release substance P which, in turn, causes a pain signal to be sent to the brain.
In addition to this pain signal triggered by the trigeminal cells coming into contact with capsaicin, your body also releases various substances. Some of these, as explained in the previous article, are endorphins, feel-good chemicals that affect your body similar to opioids.
🔪 To Seed or Not to Seed? Now that you know how capsaicin triggers your internal “smoke alarm,” find out if removing the seeds actually helps—or if it’s just a waste of time. Read our guide on Should You Remove the Seeds from Chili Peppers?
🌡️ The Thermoregulation Trick
While we perceive a burn in our mouths, our brains perceive a “fire” in our entire system. This is due to thermoregulation. Capsaicin binds to the TRPV1 receptors in your mouth and digestive tract. These are the same receptors responsible for detecting actual physical heat (like a hot cup of coffee or a literal flame).
Even though your internal temperature hasn’t actually spiked yet, your brain receives a signal that the body is overheating. Because the brain sits in a “dark box,” cut off from the outside world, it is entirely dependent on the electrical signals sent by your nerve cells. When it receives a signal from a receptor designed specifically to shout “FIRE,” the brain has no way to cross-reference the source or evaluate the truth, it can only interpret the signal as a literal threat and respond accordingly. In a desperate attempt to cool down, it triggers a false cooling response:
- Vasodilation: Your blood vessels dilate to move heat toward the skin (causing that “flushed” red face).
- Perspiration: You begin to sweat so that evaporation can cool you off.
Essentially, you feel warm and flushed because your body is reacting to a “heat” that isn’t physically there. It is a total biological hallucination.
🌡️ Measuring the Fire: We know the brain thinks there’s a fire, but how do we measure the actual intensity of the heat? Explore The Scoville Scale Explained to see how your favorite peppers are rated.
🏃 The “Chili Rush” and the Smoke Alarm Paradox
This is where the “Dark Box” confusion leads to a fascinating physiological reward. Even though your receptors are screaming “FIRE,” there is no actual tissue damage occurring.
Think of it like a smoke alarm that goes off at full volume. The brain prepares for a disaster, but as it monitors the situation, it receives no “damage signals” from the rest of the house, no charred wood, no melting structures, no actual injury. Realizing it has triggered a massive alarm for a non-existent fire, the brain pivots from defense to recovery.
To “make up” for the commotion and dull the perceived pain, the brain floods your system with endorphins (natural painkillers) and dopamine. This chemical cocktail creates the “Chili Rush”, a sensation akin to a runner’s high, accompanied by a deep, pleasant sense of warmth. It’s the brain’s version of elevator music, except in that it actually serves its intended purpose.
However, the “false alarm” has already set the body’s machinery in motion. The brain has also releases catecholamines like epinephrine (adrenaline) and norepinephrine. This is the final stage of the fight or flight response. Even though the fire wasn’t real, the resulting spike in heart rate and metabolism can actually cause your core body temperature to rise for a short period. You feel warm for a period, but you also start to feel pretty danged good. In fact, that endorphin rush is a much more powerful positive reinforcer than the initial ‘alarm’ is a negative one, which is exactly how people begin building a high chili pepper tolerance.
Further Reading
- Why Black Pepper is the King of Spices – Discover the history of the spice that ruled the world.
- Does Black Pepper Have a Scoville Rating? – Why the “bite” of black pepper is a different biological animal than the “burn” of chilis.
- The Scoville Ratings of Popular Hot Sauces – See how your favorites stack up, from Tabasco and Cholula to Frank’s RedHot and the Original Louisiana Brand.