Cranial Cooling in Contact Sport

The question

Does cooling the brain early change the course of injury?

• Short term: does acute cooling reduce symptom burden and shorten recovery after a sports concussion?
• Long term: does reducing acute thermal and metabolic load, across a career, bear on cumulative neurological risk?

Encouraging early evidence exists for the first. The second is open, and answerable only by a long, prospective effort.

What "the right way" means — discipline is the differentiator

Anyone can cool a head. Few would study it like this.

• Prospective and controlled — comparison arms and pre-specified endpoints, not anecdote.
• Applied early — cooling in the acute window, when the mechanism predicts it matters most.
• Objective endpoints — biomarkers, instrumented thermal data, and validated cognitive testing, beyond self-report.
• Clinician-governed — layered onto standard concussion care; clinical judgment governs return-to-play.
• Investigators approve the products — the study tests cooling as an approach, open to any apparatus investigators approve.
• Honest about evidence — claims sized to what is shown; the long question named as unresolved.

Study design — two arms, one investigation

The short arm earns near-term signal; the long arm addresses what matters most.

Short-term — acute recovery, within a season

• Symptom trajectory and recovery time
• Acute injury biomarkers (GFAP, UCH-L1)
• Instrumented thermal data for selected participants
• Comfort, fit, and adherence

Longitudinal — cumulative burden, across a career

• Cumulative head-impact exposure
• Longitudinal axonal-injury marker (NfL)
• Serial cognitive and recovery trajectories
• Long-horizon cohort and brain-donation linkage

A critical design principle — timing is the variable prior work underused

The metabolic cascade begins at impact, so the window for benefit is early.

• The principle. Cooling is mechanistically motivated to be applied as soon as possible after diagnosis, while the metabolic crisis is active, not after it has largely resolved.
• What earlier work missed. At least one study applied cooling roughly 24 hours after diagnosis, well outside the acute window. A delayed-application design can blunt or obscure a real effect, and may undercut its own conclusions.

This study specifies early application by design.

What the originating team brings — a low-cost device engineered to cool heads of all sizes

Thermal engineering and onboard instrumentation, contributed to a device-agnostic study.

• Conformal thermal contact — a proprietary material stack and adjustment system maintain even, effective contact across a wide range of head sizes, the prerequisite for consistent cooling.
• Onboard measurement — garment allows for supplementary sensors to quantify heat load and tissue-temperature signal during use.
• Sideline-practical — non-invasive, closed-loop, and ready within minutes, so early application is operationally feasible and affordable for wide multi-site study.

The material stack — controlled, directional, sustained cooling

Five layers, each doing one job. The stack is what makes the cooling, and the measurement, trustworthy.

Layer (environment side → skin/head)	Job
Outer membrane	Environment-side skin
Foam insulation	Blocks ambient heat
Middle membrane	Separates fill and insulation
Beads + glycerine	Thermal capacity, hold time
Thin skin membrane	Optimal heat transfer

• Why it works. The skin membrane and beads-glycerine fill deliver and hold cold at the head; the foam insulation forces heat transfer to come from the head, not the surrounding air.
• Why others fall short. Cooling products without insulation or a skin barrier sit too cold against the skin, then are quickly overwhelmed by ambient heat. The result is an uncomfortable spike followed by rapid loss of effect.

Engineering and thermal-performance characteristics; not a claim of clinical effect.

Measurement, in support — objective signals across four layers

How the study stays rigorous. No single layer is sufficient alone.

Layer	What	How
Exposure	Impact count and force	Instrumented sensors
Acute biomarkers	GFAP, UCH-L1 at the event	Rapid point-of-care assays
Longitudinal biomarker	NfL over time	High-sensitivity lab assays
Clinical & cognitive	Symptoms, balance, reaction time	Cleared platforms (ImPACT, Sway)

Sensors and iceless cooling systems allow for a fifth, intrinsic signal: onboard thermal and tissue-temperature data, allowing for measured physics in tandem with efficacy.

The collaboration — different expertise, one protocol

Each role contributes what the others cannot.

• Athletic trainers — first-line observation, early application, comfort and adherence, symptom course.
• Team physicians — clinical judgment, return-to-play, oversight of acute biomarker use.
• Researchers & labs — biomarker analysis, cognitive platforms, longitudinal data and design.

The aim is to answer the question, not to favor a device. Cooling method open to clinical investigators' judgment.

Scientific basis — what the approach is built on

Each element of the design follows from published work (citations below).

1. Concussion management is a continuum — recognition, assessment, protection, and graduated return define standard care; the study layers onto it.
2. Selective cooling shortened return-to-play — in a head-neck cooling study of ice-hockey players, cooling was associated with faster return.
3. A head-neck cooling device is feasible in contact sport — demonstrates that targeted cooling can be delivered practically in the sport setting.
4. Early safety and efficacy signal in adolescents — a randomized pilot reported preliminary safety and efficacy after concussion.
5. A measurable neurobiological effect — neuroimaging supports a biological effect of selective brain cooling after injury.

Why it matters: the study builds from the successful, on-target selective-cooling literature, not from failed whole-body hypothermia work.

Design rationale · the HALO CTP — built to deploy at scale, and to measure with precision

Two tiers, one approach: an affordable device that makes population-scale study feasible, and an instrumented tier for exacting data.

• Accessible tier — affordable conformal cooling. Material stack and adjustable straps deliver good thermal contact across head sizes, at a low price point. Why it matters: a multi-site, many-athlete, years-long study is only feasible if the intervention is affordable enough to place at high schools, colleges, and the general population.
• Instrumented tier — exacting heat-transfer data. Onboard electronics quantify heat load and tissue-temperature signal, turning the device into an instrument. Why it matters: a smaller instrumented arm validates the mechanism with precision and calibrates what the accessible device delivers at scale.

The HALO CTP is FDA Class I, 510(k)-exempt (21 CFR 890.5700). The study itself admits any clinically accepted cooling method investigators approve.

Gathering the elements — study with us

We are assembling the partners, sites, and instrumentation for a short- and long-term study of cranial cooling in contact sport, designed to be done right. We invite research groups, clinical centers, and longitudinal cohorts to join.

References

1. Patricios JS, et al. Consensus statement on concussion in sport: the 6th International Conference on Concussion in Sport, Amsterdam, October 2022. Br J Sports Med. 2023;57(11):695-711.
2. Gard A, et al. Selective head-neck cooling after concussion shortens return-to-play in ice hockey players. Concussion. 2021;6(2):CNC90.
3. Wang H, et al. A Novel Head-Neck Cooling Device for Concussion Injury in Contact Sports. Transl Neurosci. 2015;6(1):20-31.
4. Congeni J, et al. Preliminary Safety and Efficacy of Head and Neck Cooling Therapy After Concussion in Adolescent Athletes: A Randomized Pilot Trial. Clin J Sport Med. 2022;32:341-347.
5. Walter A, et al. Neurobiological effect of selective brain cooling after concussive injury. Brain Imaging Behav. 2017;12:891-900.