The palms of your hands, the soles of your feet, and the sides of your face and neck are the most effective spots to place an ice pack when you need to lower your body temperature quickly. These areas are dense with specialized blood vessels that act as your body’s built-in radiators, shuttling heat between your core and your skin surface. The classic advice to ice your neck, armpits, and groin has real merit but also real limitations, and the science over the past two decades has shifted the picture in ways that matter whether you’re an athlete cooling down after a race, a worker stuck in a heat wave, or someone helping a person in a heat emergency.
Why Certain Skin Areas Cool You Faster
Your body does not lose heat evenly across its surface. Certain patches of skin, mainly on the palms, soles, and parts of the face, contain dense networks of arteriovenous anastomoses (AVAs), which are essentially short-circuit blood vessels that connect small arteries directly to veins without passing through capillary beds. Within comfortable temperature ranges, these AVAs are the primary way your body regulates its temperature, opening and closing rhythmically to dump heat or conserve it. Blood flows through them at much higher volumes than through ordinary skin capillaries, so cooling these spots transfers cold into the bloodstream with unusual efficiency.1PubMed Central. Arterio-venous anastomoses in the human skin and their role in temperature control
Research confirms that this AVA-rich “acral” skin (the hairless skin on your palms, fingers, soles, and toes) adjusts blood flow during cooling far more aggressively than the skin on your arms or legs.2Journal of Thermal Biology. Responses in acral and non-acral skin vasomotion and temperature during lowering of ambient temperature That means an ice pack on your palm can pull heat from circulating blood more rapidly than the same pack resting on your thigh or forearm, even though those areas have more total skin surface.
Palms, Soles, and Cheeks Beat Traditional Spots
For decades, first-aid courses taught people to place ice packs on the neck, armpits, and groin to cool someone down. The logic was straightforward: large arteries run close to the skin surface in those areas, so cold applied there should chill the blood flowing to the core. That reasoning is not wrong, but a growing body of evidence suggests that the AVA-rich glabrous skin sites can outperform those traditional placements.
A randomized trial tested this directly by comparing ice packs on the palms and cheeks against the standard neck-axillae-groin placement in people with exercise-induced hyperthermia. The glabrous-skin approach cooled core temperature nearly twice as fast, dropping it about 0.30°C every ten minutes compared with 0.17°C every ten minutes for the traditional method.3Wilderness & Environmental Medicine. Novel Application of Chemical Cold Packs for Treatment of Exercise-Induced Hyperthermia: A Randomized Controlled Trial That difference adds up quickly when someone is dangerously overheated and every degree matters.
Palm cooling has also been studied in the context of athletic performance. In one trial of collegiate female athletes, using a palm-cooling device between sprints allowed athletes to complete significantly more sprints above 90% of their maximum speed compared to no cooling.4PubMed Central. The Effects of Palm Cooling on Repeat Sprint Ability Following a Fatigue Inducing Protocol in Collegiate Female Athletes The mechanism is simple: cooled blood from the palms circulates back through the body, bringing core temperature down and delaying the fatigue signal that makes you slow down or stop.
Neck Cooling and the Perception Shortcut
Even though the palms may be more efficient at lowering core temperature, cooling the neck has a unique trick up its sleeve. The neck sits close to the brain’s thermoregulatory centers, and it has exceptionally high “alliesthesial sensitivity,” which is a fancy way of saying the skin there is wired to have an outsized effect on how hot you feel. A cold stimulus on the neck can make you feel dramatically less overheated even when your actual core temperature hasn’t changed much.
A review of the research on head, face, and neck cooling during exercise found that neck cooling collars improved both endurance and repeated-sprint ability compared to no cooling, and attributed the improvement partly to this perceptual shortcut: cold on the neck directly influences how hard exercise feels.5PubMed Central. Head, Face and Neck Cooling as Per-cooling (Cooling During Exercise) Modalities to Improve Exercise Performance in the Heat: A Narrative Review and Practical Applications Separately, research on passive overheating found that cooling the head and neck region reduced feelings of heat-related fatigue and cardiovascular strain in people with elevated core and skin temperatures.6PubMed. The effect of passive heating and head cooling on perception, cardiovascular function and cognitive performance in the heat
Brain imaging studies reinforce this. When researchers scanned brain activity during passive overheating with and without head cooling, they found that cooling the head improved thermal comfort and substantially reduced the negative effects of overheating on brain function.7PubMed. The effects of head-cooling on brain function during passive hyperthermia: an fMRI study So if you can only cool one area and your goal is to feel less miserable rather than to lower core temperature as fast as possible, the neck and forehead are strong choices.
The Torso Approach and Ice Vests
Covering a large swath of the torso with cold can also be effective, simply because the chest and back offer so much surface area. Ice vests, which hold frozen or phase-change packs against the trunk, have been studied extensively in sports and occupational settings. Runners who wore an ice vest during warm-up before a hot-weather race started with a core temperature about half a degree lower than those who warmed up without one, and they finished the race with a core temperature roughly 0.6°C lower as well.8PubMed Central. Warming up with an ice vest: core body temperature before and after cross-country racing In track athletes, wearing a cooling vest during warm-up improved 5-kilometer run times by about 13 seconds, with the benefit showing up most in the later stages of the race, when heat buildup normally forces runners to slow down.9PubMed. Cooling vest worn during active warm-up improves 5-km run performance in the heat
Wearing an ice vest during exercise, not just before it, has its own benefits. In cyclists working hard in warm, humid conditions, wearing an ice vest throughout exercise reduced thermal strain and improved performance.10Journal of Thermal Biology. Adding a cooling vest during cycling improves performance in warm and humid conditions However, one study found a paradox worth knowing about: wearing an ice jacket lowered torso skin temperature and perceived thermal discomfort during repeated sprints, but it did not translate into measurably better sprint performance, and core temperature was unchanged.11PubMed. Effect of wearing an ice cooling jacket on repeat sprint performance in warm/humid conditions The lesson is that torso cooling reliably makes you feel cooler, and in sustained efforts that benefit usually translates into pacing yourself less conservatively, but in short explosive bursts the benefit may be mostly comfort.
What the Temperature of the Cold Pack Matters
Not all cold packs cool equally, and the temperature of the cooling material matters more than you might expect. A study comparing cooling vests with packs that melted at different temperatures (0°C, 10°C, 20°C, and 30°C) found that only the two coldest vests provided meaningful cooling during active exercise. During rest, all four provided some benefit, but the colder ones still extracted substantially more heat.12PubMed. The impact of a phase-change cooling vest on heat strain and the effect of different cooling pack melting temperatures If you’re sitting under a fan in a warm room, a lukewarm gel pack might do something. If you’re exercising hard or working outdoors, you need something genuinely cold.
The type of cold agent also makes a difference. When researchers compared crushed ice, wetted ice (a slurry of ice and water), gel packs, and frozen peas, the crushed ice and wetted ice were the clear winners, producing deeper and more sustained drops in skin temperature. Gel packs and frozen peas lagged well behind.13PubMed Central. Cooling efficiency of 4 common cryotherapeutic agents The reason is partly about thermal mass and partly about contact: ice and water mold to the skin surface and maintain even contact, while gel packs may leave air gaps, and frozen peas are lumpy by nature.
What Happens Under the Skin When You Apply Cold
When you place an ice pack on skin, the surface temperature plunges quickly. In one study, skin temperature dropped about 27°C over 30 minutes of cooling, while the muscle underneath cooled by only about 8°C, and core temperature drifted down a modest 2°C.14Archives of Physical Medicine and Rehabilitation. The relationship between intramuscular temperature, skin temperature, and adipose thickness during cryotherapy and rewarming That steep gradient between skin and deeper tissue is important for two reasons. First, it explains why cooling whole-body core temperature with a single ice pack is slow: the skin gets very cold very fast, but that cold penetrates deeper tissue at a much reduced rate. Second, it means the skin itself bears the brunt of the thermal stress, which is where frostbite risk comes from.
Your body also actively fights the cooling. Cold-sensing nerves trigger vasoconstriction, which narrows blood vessels in the chilled area and reduces blood flow to the skin.15PubMed. Skin vasoconstriction as a heat conservation thermoeffector This is your body’s way of conserving core heat, but it works against you when you’re trying to cool down: constricted blood vessels mean less blood is flowing past the cold surface to be chilled and carried back to the core. That vasoconstriction can persist well after the cold source is removed, sometimes for hours.16PubMed Central. Cold-induced vasoconstriction may persist long after cooling ends: an evaluation of multiple cryotherapy units
This is actually one of the arguments for cooling the palms and soles. Because the AVAs in those areas are designed to stay open for heat dissipation, they may resist vasoconstriction under moderate cooling better than ordinary skin, keeping the blood-to-cold-surface exchange going. However, if the cold stimulus is too intense, the AVAs clamp shut as well, and you lose the advantage. Some researchers in the palm-cooling space have found that a mildly cool surface (around 10-15°C) keeps the AVAs open better than ice-cold contact, which is counterintuitive but physiologically logical.
Cardiovascular Side Effects of Cold Application
Putting cold on the neck, head, or face doesn’t just affect temperature. It also triggers reflexes that change heart rate and blood pressure. Applying ice to the forehead and face has been shown to slow heart rate and lower blood pressure, possibly through withdrawal of sympathetic nervous system drive rather than direct parasympathetic activation.17PubMed Central. Effect of Ice Massage to Head and Spine on Blood Pressure and Heart Rate Variability in Patients with Hypertension: a Pilot Study Neck cooling specifically has been shown to raise blood pressure (by about 11 mmHg systolic and 8 mmHg diastolic in one study of healthy volunteers) and trigger peripheral vasoconstriction that dramatically cut blood flow to the fingers.18PubMed Central. Neck cooling induces blood pressure increase and peripheral vasoconstriction in healthy persons
For most healthy people, these reflexes are temporary and harmless. But for someone with uncontrolled high blood pressure, certain cardiac arrhythmias, or a condition like Raynaud’s phenomenon (where cold triggers exaggerated vessel spasm in the fingers and toes), aggressive cold application to the neck or face could be problematic.19PubMed. Cold-induced cutaneous vasoconstriction in humans: Function, dysfunction and the distinctly counterproductive If you have a cardiovascular condition, err on the side of cooling the palms or using a cool towel on the forehead rather than wrapping a frozen pack around your neck.
When the Stakes Are High: Heat Stroke
Everything discussed so far applies to everyday overheating and exercise-related heat management. Heat stroke is a medical emergency with different rules. In exertional heat stroke, which happens to athletes, soldiers, and outdoor workers, full-body cold water immersion is the gold standard: you get the person into a tub or kiddie pool filled with cold water. Case series with this approach show a zero fatality rate in younger, fit patients when cooling is initiated promptly.20The Journal of Emergency Medicine. Cooling Methods in Heat Stroke
Ice packs placed on the neck, armpits, and groin, the method many people think of first, are not recommended as a primary cooling method for heat stroke. They simply don’t cool fast enough. The same review found that for older patients with classic (non-exertional) heat stroke, evaporative cooling with convective airflow (misting the skin and blowing fans) is generally preferred, and ice packs applied broadly over the body can supplement that approach but shouldn’t be relied on alone.20The Journal of Emergency Medicine. Cooling Methods in Heat Stroke The irony is that methods using convection and evaporation, rather than conduction (direct contact with cold), tend to outperform ice packs in true hyperthermia because they cool the whole skin surface at once.21Clinical Infectious Diseases. External Cooling in the Management of Fever
A trial comparing body-cooling methods for mildly hyperthermic athletes found that cold water immersion, an ice-slurry-based cooling system, and an iced towel protocol all lowered rectal temperature significantly more than passive cooling in the shade after just 10 minutes.22The Journal of Strength & Conditioning Research. Comparison of Body Cooling Methods on Physiological and Perceptual Measures of Mildly Hyperthermic Athletes The consistent theme is that the more skin area you can cool, and the more efficiently you maintain contact between the cold medium and the skin, the faster core temperature drops. A single ice pack on one body part, no matter which one, has limits.
Practical Tips for Everyday Cooling
If you’re just trying to cool off after a run, during a heat wave, or while working outside, you don’t need a laboratory setup. Here’s how to get the most out of what you have:
- Palms first: Hold a cold water bottle or rest your palms on a bag of ice. This takes advantage of the dense AVA network, and your hands are conveniently accessible. Don’t grip something so cold it hurts; moderately cold (a chilled water bottle, ice wrapped in a thin cloth) may keep blood vessels open better than bare ice.
- Neck for comfort: A wet bandana, cold towel, or commercial neck wrap on the back and sides of the neck will make you feel dramatically cooler. It won’t lower core temperature as fast as palm cooling, but the perceptual relief is powerful and nearly instant.
- Feet if available: Soaking your feet in cool water is an old trick that the science actually supports. The soles are loaded with AVAs, and water provides far better thermal contact than air.
- Combine sites: Using two or three sites at once (palms plus neck, or feet plus forehead) multiplies the cooling surface area. If you have multiple cold packs, distribute them rather than stacking them all in one spot.
- Use real ice or wetted ice: If you have the choice, a bag of crushed ice or ice-water slurry will cool faster and longer than a gel pack or a bag of frozen vegetables.
Avoiding Cold Injuries
The risk of frostbite from a household ice pack is low but not zero. Case reports document frostbite from chemical cold packs applied directly to skin for extended periods, particularly when a person falls asleep or has reduced sensation in the area.23PubMed Central. Preventable frostbite due to cold pack A thin cloth barrier between the pack and your skin, and limiting direct application to around 20 minutes at a time, are standard precautions. Pay attention to numbness: if the skin under the pack goes from uncomfortable cold to a complete absence of sensation, remove the pack.
Prolonged cold application also causes vasoconstriction that can persist for hours after the ice is removed, and in extreme cases this sustained blood-flow reduction can cause nonfreezing cold injury, a form of tissue damage from ischemia rather than ice crystal formation.16PubMed Central. Cold-induced vasoconstriction may persist long after cooling ends: an evaluation of multiple cryotherapy units This matters less for brief everyday cooling and more for clinical situations where ice packs are applied for long stretches, such as post-surgical recovery. But the principle applies universally: use cold for cooling, not for punishment. Once you feel cooled down, take the ice off.
Why “Cooling Down” and “Icing an Injury” Follow Different Rules
People sometimes conflate ice-pack placement for cooling the body with ice-pack placement for treating an injury like a sprained ankle or sore knee. These are different goals with different logic. When you ice a sprained ankle, you’re trying to constrict blood vessels locally to reduce swelling in that specific joint. You want the vasoconstriction effect, and you want the cold to penetrate the tissue underneath the pack. When you’re trying to cool your whole body down, vasoconstriction is your enemy: it throttles the very blood flow that carries heat away from your core to the cold surface. That is why choosing AVA-rich sites (palms, soles, face) gives you an advantage for whole-body cooling. Those blood vessels are built to stay open for heat exchange, so they resist the vasoconstriction reflex better than ordinary skin and keep circulating warm blood past the cold stimulus.
This distinction also explains a puzzling finding in the heat-stroke literature: ice packs on the groin and armpits, which seem like they should cool the blood in the femoral and axillary arteries, don’t work as a standalone treatment for serious hyperthermia. The skin around those arteries still constricts in response to cold, reducing contact between chilled blood and the cooling source. Whole-body water immersion bypasses the problem by cooling so much skin surface simultaneously that vasoconstriction in any one zone barely matters.