Getting into cold plunging can feel a bit like joining a club (of the coolest kind).

And just like many hobbies, the deeper you go, the more you’ll learn about the shared language of this community of ice bath enthusiasts.

Here’s a glossary of cold-plunge terminology to show off your ice bath IQ to your new crew.

Thermal layer

Definition: The thin layer of water closest to the skin.

What it means: Heated by a person’s body heat, the water nearest your skin is slightly warmer than the surrounding water. Movement — such as the current of a stream, a water circulation system or moving you body — breaks up this layer and can make your cold plunge feel more intense.

How to use it: “If you’re feeling up to it, move your arms and legs to break up the thermal layer for an added challenge”

Parasympathetic nervous system

Definition: Often referred to as the “rest and digest” system, the parasympathetic nervous system helps the body conserve energy and recover by slowing down heart rate, promoting digestion, and relaxing various physiological processes.

What it means: It’s the counterbalance to the sympathetic nervous system, which triggers our fight-or-flight response. When we enter cold water, we’re forcing our body into the fight-or-flight state. By maintaining focus and control while in an ice bath, you’re also activating the parasympathetic nervous system and teaching your body how to handle stress.

How to use it: “The first 30 to 60 seconds is the hardest part. Once you get past that, you’ll activate the parasympathetic nervous system and get into a flow”

Brown fat

Definition: Also known as brown adipose tissue (BAT), this specialized fatty tissue generates heat through a process known as thermogenesis.

What it means: Unlike white fat, brown fat uses stored energy to produce heat. In cold plunging or exposure to cold temperatures, the activation of brown fat helps to maintain core body temperature and burn calories, making it a valuable component of cold adaptation and, potentially, weight management.

How to use it: “Did you know brown fat is actually considered ‘good fat?'”

Intention

Definition: A specific goal or purpose set before entering cold water.

What it means: Having a clear intention can serve several purposes. It can make you more mentally prepared for the cold shock, foster a positive mindset or direct your attention toward the desired outcome of the cold immersion experience. Intention-setting in cold plunging can help you stay focused, manage your reaction to cold exposure and maximize the potential benefits of the practice.

How to use it: “Before we get in, let’s take a moment to set an intention. What are you hoping to get out of this experience?”

Box breathing

Definition: This mindfulness and relaxation technique involves a specific pattern of controlled, rhythmic breathing. It typically consists of four equal phases: inhale, hold, exhale, and hold, each lasting for the same duration. For example, inhaling for four seconds, holding for four seconds, exhaling for four seconds, and holding for four seconds before repeating.

What it means: Box breathing is often used to reduce stress, promote mental focus and manage anxiety, which can be beneficial before or after cold plunging to help maintain composure. Focusing on your breath before an ice bath can help you activate the parasympathetic nervous system.

How to use it: “Let’s take a minute to focus on our breath before we get in the ice bath. How about a few rounds of box breathing?”

Cold shock proteins

Definition: Cold shock proteins, also known as cold-inducible proteins or stress proteins, are a group of specialized proteins that the body produces in response to sudden cold exposure or other forms of physiological stress.

What it means: These proteins help protect cells and tissues from damage caused by extreme cold or other stressors. The production of cold shock proteins is part of the body’s adaptive response to cold, and they play a role in mitigating the negative effects of cold shock on cellular integrity.

How to use it: “Did you know even 20 to 30 seconds of cold water at the end of your shower is enough to get a boost in cold shock proteins?”

Hormetic stress

Definition: A beneficial, low-to-moderate level of stress or challenge that triggers adaptive responses and ultimately leads to improved resilience and health.

What it means: In the context of cold plunging, exposure to cold water or cold temperatures can be considered a hormetic stressor. By subjecting the body to controlled cold stress, hormetic responses such as increased brown fat activation, improved circulation, and enhanced immune function can be stimulated, contributing to overall health and well-being.

How to use it: “Taking an ice bath is a great way to introduce hormetic stress to your body, which can lead to increased strength and resilience over time.”