General FAQs

What are Halo® Active Helmets?

Halo® Active Helmets are unique motorcycle helmets developed by Halo® Active Technology, that deliver brain cooling to you, the end user, in the case of a head injury.

Halo® Active Helmets activate at the moment of impact, mixing ammonium nitrate and saline in solution. This chemical reaction is endothermic; it absorbs heat energy. This cools the enclosed, injured brain of the Halo® active helmet wearer for 30-45 minutes. 

What is the Golden Hour?

When doctors discuss brain injury, the concept of the 'Golden Hour' reigns supreme. This refers to first sixty minutes following impact, when the extent of an injury is typically determined. With the correct, immediate medical care, the development of called 'secondary injury' around the focus of primary injury can minimised.

Unfortunately for you as a motorcyclist, there is an inherent gap in the chain of survival during this Golden Hour due to the delays in definitive medical care arriving to the accident scene. This eats into your Golden Hour, potentially affecting your mortality (chances of death) and morbidity (chance and extent of disability). Read more about brain injury.

Why is the Halo® Active Helmet's brain cooling important?

When activated, a Halo® Active Helmet cools the wearer's head to combat the malignant heating effects (hyperthermia) caused by brain inflammation following traumatic brain injury. These effects contribute to the extending zone of secondary injury during the Golden Hour. Logically preventing brain hyperthermia improves your chances!

Halo® Active Helmets also offset the insulating, heating effect of a helmet that all riders will be familiar with - they are hot to wear! Without a Halo® Active Helmet, while protecting your head at the moment of impact, the insulating foam in your regular helmet could subsequently do more harm than good.

How does a Halo® Active Helmet compare to my existing helmet?

Halo® Active Helmets have been proven to be at least as safe as existing helmet designs for passive safety - that is, they are designed to absorb as much of the impact of a collision as existing designs do.

Halo® Active Helmets go beyond this, since some features of the exterior shell's design are actually favourable compared to existing helmets.

Halo® Active Helmet's completely unique difference however is that it goes on protecting you in the aftermath of the accident, through the brain cooling effects described above. By patent, no other helmet can provide this protection to you.

Halo® Active Technology's mission is to put Halo® Active Helmet's disruptive technology directly in the hands of the people who stand to benefit - you.

What is the ‘Halocator’ Emergency Beacon Transmitter?

An optional Emergency Beacon Transmitter can be fitted to your Halo® Active Helmet, which activates at the moment of an accident. It transmits GPS-based location data via the mobile phone network to a base station. Using the established one-time telephone connection staff can determine with you whether medical attention is required, and dispatch accordingly. Lastly, the mobile network can automatically inform up to ten nominated people of the event by text message.

Can Halo® Active Technology be retrofitted?


Halo® Active Technologies takes pride in providing the complete Halo® active helmet package, incorporating our range of other innovative technologies, to ensure the highest standards of manufacturing and performance quality. We simply could not ensure the same standards retrofitting our Endothermic technology into other manufacturers' helmets. 

Who else may benefit from Halo® Active Technology?

Halo® Active Technology is highly adaptable to different needs. Initial efforts have resulted in the HALO® C-TEC1 motorcycle helmet. Subsequent technology applications currently in development are:

Fire and Emergency services

Industrial and manufacturing


Equine Sports

Snow sports

If you are at risk of a head injury at home or on transport, or if your sport demands a helmet, the chances are that in the coming period Halo® Active Technology will have announcements for products incorporating our technology relevant to you. Click here to keep updated.

Medical FAQs

What is the evidence base behind Halo® Active Technology?

The inspiration behind Halo® active technology draws on a diverse literature, all of which converges on the concept of brain cooling:

  1. There is considerable in-vitro work that supports cooling brain tissue to minimise hyperthermic inflammatory damage, by slowing enzyme cascades, reducing hyperaemia (increased blood flow) and oedema (swelling) effects
  2. In vivo, the cooling of other organs is already in use to slow their metabolic rate in some routine clinical scenarios
  3. n the middle ground there are various animal studies of brain cooling for brain injury, as well as some small studies in humans that have shown variable degrees of benefit.
  4. The breadth of these sources conveys the biological plausibility of brain cooling for reducing traumatic brain injury in humans. What is currently lacking is a sufficiently large, 'real world' trial to establish and quantify efficacy

What limits the evidence in humans?

Conducting a gold-standard randomised, placebo-controlled, adequately blinded trial of brain cooling is impossible, being arguably unethical: that we cannot crash motorcyclists, with and without Halo® active helmets, and observe the results in order to quantify the benefit that may be gained by Halo® active helmet wearers, is obvious.

As with the development of other potentially life-saving treatments, new chemotherapy drugs for example, the use of brain cooling in current clinical practice is typically as a 'last ditch' technology used in only the very worst cases. These studies can provide little sense of the potential of brain cooling overall, nor are they generally powered sufficiently to probe for potential benefit.

Equally, whenever brain cooling has been applied, it’s been achieved by such a diverse range of methods, and results vary to such degrees, that attempts to pool this heterogeneous data and discover an 'answer' fail to give a conclusive result.

It is important to note that the present lack of evidence is absolutely not the same as there being any positive evidence against the use of brain cooling. It is also important not to link the Halo® effect to recent negative reports on total body cooling in a clinical setting, where patients’ whole body temperatures were reduced to sub-zero degrees for days. Our aim is to reduce serious increases in temperature and maintain a normal temperature in the ‘golden hour’.

Where might such evidence come from?

There is much clinical work that demonstrates and recommends the benefits of cooling to prevent further damage to any organ and to accelerate healing. However currently there is no definitive work around brain cooling during the golden hour to finally establish the clinical effectiveness that is presently 'suspected'. 

Halo® itself may provide the answer - If the product is as widely adopted as hoped, this will provide a great deal of data regarding a single, homogenous, practical, real-world application of brain cooling. The analysis of outcomes from accident statistics should allow quantification of the benefits of Halo®.

What about the existing Cochrane reviews?

Cochrane reviews summarise existing evidence for specific clinical scenarios.

As described above, the existing primary research evidence base is poor at least in part for ethical and practical reasons when conducting research, and the Cochrane reviews simply reflect this poor quality.

Equally, in the case of brain cooling, the clinical scenarios generally envisaged apply to the actions of an emergency physician in a hospital setting, not an 'at the scene' immediate-response technology. Drawing comparisons between the Halo® active helmets scenario and those that form the basis of the Cochrane reviews is therefore unfounded.

Could Halo® Active Helmets brain cooling be dangerous? 

Halo® active helmet technology is designed to keep the brain approximately normothermic (at normal temperature) in the face of increased heat production following traumatic brain injury, rather than to achieve substantial drops in brain temperature as is the more typical aim in specialist secondary care units. Consequently Halo® active helmet technology aims to avoid positively dangerous hyperthermia, rather than produce uncontrolled, potentially damaging degrees of hypothermia (low temperatures).

The constituents of the cooling device itself are chemically unharmful, and the device itself has features to prevent the cooling medium coming into direct contact with the Halo® active helmet wearer.

On What Basis Are Halo® Active Helmets Being Sold? 

HALO® C-TEC1 motorcycle helmet technology is adjuvant to conventional helmet technology. HALO® C-TEC1 motorcycle helmets have been proved as safe as existing helmet designs, in the conventional 'impact energy dissipation ‘sense. It then adds the potential additional benefit of brain cooling.

It is not claimed that every user or indeed even a majority of users will benefit from HALO® C-TEC1 motorcycle helmet technology, just as seatbelts or conventional helmets cannot help every accident victim. However it is expected that some users will benefit, and it is on this 'as good as if not better than your old helmet' basis that HALO® C-TEC1 motorcycle helmets are being sold.

Will the Halo Active helmet work in every case? 

Our Helmets have been tested in accordance with all required legislation. Rigorous tests also proved the Halo endothermic system works, in specific test conditions. However we cannot claim the helmet’s technology will work in every accident, as there is no way to devise tests to account for the multitude of different circumstances riders will face. It is also known that the Halo® endothermic reaction will not be activated if the rider lands on the ‘dome’ of the helmet (i.e. the very top section), however such landings only happen in approximately 4% of recorded accidents.

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