Bath bombs can produce endothermic reactions that cool water

Our bodies cool us down by sweating because water requires a significant amount of energy to change state from liquid to gas, making it an ideal medium for carrying thermal energy away from our bodies.

Electricity is produced when the ends of a battery are connected by a conducting wire, triggering chemical reactions that release the energy stored in chemical bonds.

Scientific applications of bubbles include logic gates, laser production, and medical imaging

Microbubbles of nonreactive gas can be administered to improve the reflection of sound waves and the resulting imaging during an ultrasound. Bouncing light waves within a bubble can stimulate emission of light from a trapped chemical, just as occurs within a laser, and bubbles can act as valves that control the flow and reaction rates in microfluidic systems.

Laundry detergents designed for cold-water washes rely on proteins isolated from microorganisms native to cold climates, such as Iceland.

Watch a server submerged in a fluid continue to run and stay cool by boiling the liquid away.

In nuclear reactors, water acts as a coolant and moderator, slowing neutrons produced in nuclear reactions so they are more likely to interact with nuclear fuel and generate sustainable energy.

Sand 'batteries' can store excess electricity from the power grid as thermal energy

Energy collected from solar or wind power is used to heat insulated silos full of sand to temperatures as high as 450 degrees Celsius (842 degrees Fahrenheit), which can be retained for long periods. These thermal energy storage systems can be designed to boil water and generate electricity when needed.

Reduced inflammation from cold plunges lacks scientific support

The cold water triggers immediate cold shock, increasing heart rate and blood pressure, and prolonged exposure can lead to cold-water incapacitation and hypothermia. Plungers are encouraged to enter the water slowly and manage their breathing to reduce the risk of shock. Warm baths post-plunge are discouraged, and exercise is generally better for recovery.

Heat pumps use an easily boilable chemical to regulate temperature

In air conditioners, warm air is pulled from a home to turn a refrigerant into a gas, which is then compressed, raising its temperature. The gas naturally releases this energy to the comparatively cooler environment when exposed, then expands and is reused in the system. Heaters run in reverse, with the refrigerant picking up energy from the comparatively warmer environment.

Catalysts increase chemical reaction rates by providing a lower energy pathway

All chemical reactions must overcome an energy barrier, called an activation energy, to proceed. If insufficient thermal energy exists in the system to overcome the barrier, catalysts can effectively lower the activation energy, increasing the likelihood of reactions occurring.

Batteries are likely to stop working sooner in cold temperatures

The electrolyte separating the cathode and anode of a battery can thicken, impeding ion flow. Lower temperatures also slow the rate of chemical reactions, further reducing battery capacity. Large draws of power, such as when using heaters, heated seats, etc., in a car during winter, exacerbate battery drain further.

Spontaneous combustion involves an object igniting on its own

Even without matches, sparks, or external flames, exothermic chemical or biological reactions can increase the internal temperature of objects to the point where they reach a threshold temperature that can cause them to catch fire. Running batteries and fermenting bacteria within compressed materials can build this heat and cause combustion.

Thermal runaway reactions can cause batteries to catch fire or explode

If a lithium-ion battery is heated, punctured, crushed, or short-circuits due to manufacturing flaws or degradation, the cathode and anode can make contact without the resistance provided by a circuit. The ensuing spike in chemical reactions increases the temperature and can release oxygen, initiating and intensifying burning of the battery's interior.

Health workers may cool body temperatures with convection cooling

That's spraying a patient with water and putting fans over them. Cooling the body by removing clothing and placing cold water and ice packs—and not blocking evaporation—are essential cooling steps.

Watch an animation of what happens inside cookies as they bake in an oven

As temperatures rise and butter melts, trapped water expands, spreading the dough, which remains held together by a network of proteins. Maillard reactions produce browning on the surface beyond 310 degrees Fahrenheit (154 degrees Celsius), while caramelization can be triggered by baking past 356 degrees Fahrenheit (180 degrees Celsius).

Breaking down the challenges of alkaline environments and how extremophiles survive them

These areas are far less acidic than the interiors of most organisms' cells, and this imbalance draws protons that are needed for various metabolic processes, including energy production, out of cells. To counter these effects, some alkaliphiles have developed stronger proton regulation across their cellular membranes and proteins that drive these processes with greater stability amid such acidity imbalances.

Cold water swimming can induce positive stress

The tradition of cold water swimming (or taking a cold plunge, or even a cold shower) has been shown to release the same hormones triggered during a stress response. This can have the effect of increasing blood flow, improved mental acuity, and more.

Alkaline hydrolysis—dissolving the body—is one 'green' burial option

This approach, which is sometimes called flameless cremation, involves dissolving the body with water and chemicals. The remaining bone fragments can then be spread like ashes. It was reportedly incorporated into the funeral industry in 2011.

Understanding the biochemistry of ingredients and taste can improve flavor and texture

Keeping eggs at room temperature produces smoother batters when baking, and doing the same with tomatoes helps prevent a mealy, granular mouthfeel. Salting meat a day before gives more time for proteins to break down, improving flavor and tenderness, while cooking vegetables in well-salted water can lock in nutrients and color.

Some materials can absorb low-energy light and emit high-energy radiation

Through anti-Stokes cooling, incoming energy is combined with vibrations in a material's crystal lattice to produce a net reduction in its temperature. Using this effect, lasers can be directed at microchip hot spots to help keep data centers cool.

Metabolism, a collection of chemical reactions at the cellular level, processes food and converts it into energy to power the body.

View thermophiles found in Hot Springs National Park, including nanobacteria and ostracods

Most organisms in this subset of extremophiles live at temperatures between 60 and 80 degrees Celsius (140 to 176 degrees Fahrenheit), which is hot enough to unfold proteins needed for most biochemical reactions. In thermophiles, these molecules, including those needed to replicate DNA during cellular division, are tightly packed and held by stronger bonds to resist changes in shape.

The composition of magma affects the explosivity of volcanic eruptions

Silicate-rich magma contains extensive molecular chains that trap dissolved gases like water and carbon dioxide. These gases build pressure until they violently escape, creating explosive eruptions. Low-silica magmas produce gentler eruptions categorized as effusive.

Data centers can be kept cool by circulating fluid over plates atop high-temperature components or by submerging equipment in non-corrosive oil that does not conduct electricity.

Simple home improvements like proper insulation can reduce winter energy bills

To save money in the colder months, some experts recommend washing your clothes in cold water, using your dishwasher instead of washing dishes by hand, and more. This article lists even more winter money-saving tips.

Explore the chemical compounds found in fireworks

Besides the various salts and metals used to produce fireworks colors, shells are also filled with gunpowder and oxidizers to help fuel and accelerate reactions. Chlorates help strengthen colors, while dextrin, a starch, helps hold mixtures together.

Certain medications that affect blood flow or mood boost the risk of heatstroke

Drugs that narrow blood vessels, beta blockers that regulate blood pressure, diuretics, antidepressants, and antipsychotics can all affect the body's ability to regulate its internal body temperature, and so individuals taking these medications need to take special care in extreme heat and when exercising in hot conditions.

The warmest waters in the ocean are found at hydrothermal vents—hot springs on the seafloor that discharge plumes of mineral-rich water.

Since the Industrial Revolution, surface ocean waters have become 30% more acidic due to the absorption of carbon dioxide.

Solid-state batteries substitute the fluid electrolyte layer with a solid

The non-flammable solid greatly reduces the risk of fire and explosion, as well as the release of toxic gases via leaks in the existing sulfide-based systems. These batteries use garnet-type solid electrolytes, which provide high ionic conductivity and chemical stability but require temperatures above 1,000 degrees Celsius (1,800 degrees Fahrenheit) for fabrication.

Desalination involves costly, energy-intensive methods for producing freshwater

Thermal desalination heats saltwater to produce steam, and reverse osmosis forces saltwater through a membrane that only allows water through. In both cases, freshwater is collected and remineralized for consumption, while wastewater brine is often returned to the ocean, where it may harm marine organisms.

Some data shows cold showers can help with depression

An icy water exposure can lead to the release of norepinephrine, cortisol, dopamine, and other stress hormones that are beneficial, among other potential effects. Some data shows that this type of exposure can help combat depression symptoms among some patients, but more research is still needed. (Some users may encounter a paywall.)

High-frequency sound waves have been used to brew espresso with room-temperature water and about one-fourth the energy of a traditional espresso machine, which relies on hot water and pressure.

While both are nuclear weapons, atomic bombs release nuclear energy by splitting large atomic nuclei, whereas hydrogen bombs derive most of their energy from fusing heavy hydrogen isotopes.

Since 2026, the Large Hadron Collider has provided heat to thousands of French homes and businesses through a system that harnesses hot water from the accelerator's cooling circuits.

Watch a demonstration of the greenhouse effect with carbon dioxide, where thermal energy is trapped by the gas within a container, causing the temperature to increase.

Why do you shiver when cold?

Humans are warm-blooded creatures, so our bodies like to maintain internal temperatures separate from and typically above those in their environment. This is made possible by a process known as thermoregulation. When the brain's hypothalamus senses a drop in the body's core temperature, skeletal muscles may be ordered to shiver, sending out waves of muscle contractions and exothermic biochemical reactions whose byproduct includes heat and energy.

Glow sticks feed energy released in chemical reactions to fluorescent dyes

When bent, the glass tube inside the stick breaks, releasing hydrogen peroxide into the surrounding solution. The ensuing reaction creates unstable molecules that decompose and release energy, which is then absorbed by molecular dyes that emit light when their excited electrons return to lower energy states.

Explaining why salt should be used to season food early in the cooking process

Experiments involving the same dishes, with salt added at the start of cooking versus at the end, have been shown to yield drastically different taste outcomes because salt takes time to diffuse into foods, particularly vegetables, whose cells are surrounded by cellular membranes and walls. Salting at the end will produce a concentrated surface coating, rather than even seasoning.

The ocean gets its salt from runoff carrying fragments of eroded rock and from seawater dissolving salts and minerals from magma at seafloor spreading centers.

How fermentation enables the pickling of food and the production of beer

This process occurs when microbes produce lactic acid, ethanol, or carbon dioxide after consuming sugars. The acid helps preserve vegetables in a brine solution during pickling and gives them a sour taste, while ethanol serves as the inebriant in alcoholic beverages. The acid and carbon dioxide give sourdough bread its taste and texture.

When bleach comes into contact with oily skin, it forms soap—the combination of an alkaline, non-acidic substance with a fat.

Instead of consuming water and carbon dioxide to produce oxygen and sugar, anoxygenic photosynthesis involves alternative reactants and products.

Barbecue relies on a unique scientific equation

Barbecue's distinct flavor starts with an interaction between the heat source and food, which creates a Maillard Reaction—better known to diners as those crunchy, caramelized bits on the outside.

Under certain conditions, very hot liquids can freeze more quickly than cooler ones—a phenomenon called the Mbemba effect, after the Tanzanian high school student who accidentally observed it.

The history of soap and how it forms bathtub scum and white spots in old oil paintings

Soap has been produced since at least 2,200 BCE via a chemical reaction between fats or oils and a base. This creates salts that act as molecular bridges, helping water lift dirt and grease from surfaces. The same chemistry produces scum when metals in hard water bind to soap molecules, as well as white spots in paintings when metal ions in pigments react with fatty acids in the oil binder.

A look at hydrothermal vents, where barophiles and hyperthermophiles survive boiling water

Discovered in 1977 during an exploration of the Galapagos Rift, these seafloor openings spew hot magma and chemicals that heat seawater to hundreds of degrees. Without the sunlight found at depths of less than 1,000 meters (3,281 feet), extremophiles in these environments convert released chemicals into energy to survive, alongside surviving extreme pressures.

Watch underwater photosynthesis make water look like champagne

In shallow waters where sunlight can reach, photosynthetic reactions absorb water and dissolved carbon dioxide, producing bubbles of oxygen at the surface of plants. As these bubbles rise to the water's surface, a fizzy appearance is created.

Through sonoluminescence, concentrated sound waves can produce short, high-intensity flashes of light by rapidly collapsing microscopic bubbles to temperatures up to twice that of the sun's surface.

Pure water does not conduct electricity because this flow of energy requires the movement of charged particles, and water is a neutral molecule.