A simple, trained 30-second head dunk rapidly cools overheated dogs

When a dog’s core temperature rises above roughly 105 °F, the risk of organ dysfunction and death climbs sharply, and early, effective field cooling can be lifesaving. Recent trials from the Penn Vet Working Dog Center directly compared several field-feasible cooling strategies and produced results that may change how clinicians approach prehospital management of heat injury. These studies are the research behind Cynthia M. Otto, DVM, PhD, DACVECC, DACVSMR’s recognition as an AKC Canine Health Foundation Health Discovery Award finalist.^1-3

Why rapid cooling matters

Working dogs are at a greater risk because drive and motivation can override physiologic cues to stop. As Otto said to AKC, many dogs will “just go, go, go” until collapse, which places responsibility on clinicians to intervene before irreversible injury occurs. The Penn Vet group set out to determine which simple, portable cooling measures produce the most rapid reduction in core body temperature after exercise-induced hyperthermia so that veterinary professionals would have practical, evidence-based options in the field. ^1-3

Field-tested cooling methods

In a randomized crossover trial published in Animals (Basel), investigators compared partial water immersion, application of isopropyl alcohol to the paw pads, and passive cooling in 11 working dogs after standardized exercise. Partial water immersion cooled dogs more quickly than either isopropyl alcohol or no intervention; dogs that were passively cooled in shade frequently continued to warm for the 20-minute observation period, underscoring that rest alone is often insufficient and that active cooling is required. Notably, isopropyl alcohol did reduce core temperature relative to no intervention, but its application was associated with elevated heart rates, which could blunt the cooling benefit and has practical safety concerns such as topical irritation and flammability.²

Building on those findings, a separate Penn Vet randomized crossover study reported in the Journal of the American Veterinary Medical Association evaluated several field methods that clinicians could realistically deploy, such as neck ice packs, wet neck towels, wet axillary towels, and a trained voluntary head immersion lasting about 30 seconds into approximately 70 °F (≈22 °C) water. The most striking and reproducible result was that the trained voluntary head dunk produced the most rapid early reduction in core temperature and was the only method that prevented the transient rise in temperature often seen immediately after stopping strenuous activity. In other words, when dogs were trained to voluntarily dunk their heads (for a toy or food reward), a brief head immersion produced measurable cooling within minutes and yielded sustained early benefit compared with the other field protocols tested.³

The physiology behind this effect is straightforward: dogs dissipate much of their heat through panting, which increases blood flow to the head, muzzle, and nasal turbinates. Cooling those well-perfused tissues by conduction by submerging the head to the level of the eyes or ears rapidly cools blood returning from the head that then circulates systemically, lowering core temperature more quickly than surface cooling of the limbs or trunk alone. The Penn Vet authors emphasize that this is a targeted, physiology-based intervention that is simple to train and deploy when water is available.³

When to use a head dunk

These papers also highlight important limitations in clinical practice. Both trials enrolled small numbers of working dogs in training (11 to 12 dogs), which limits generalizability to the broader pet population, to brachycephalic, geriatric, or debilitated animals, and to dogs that present with severe heat stroke and altered mentation. The voluntary head dunk was deliberately evaluated only in dogs that were cooperative and had normal mentation. Dogs that are obtunded, seizuring, or unable to protect the airway are not candidates for a voluntary dunk and require aggressive, supervised emergency cooling and immediate transport. Moreover, the head dunk’s effectiveness depends on prior training and handler skill. An untrained, uncooperative dog will not benefit.^2,3

From a practical standpoint, these findings appear to support the idea that passive rest alone is not adequate. Feasible partial or whole-body water immersion is preferred. When immersion of the body is impractical, but the dog is cooperative and alert, a short, trained, voluntary head dunk offers the most rapid early cooling. Across all scenarios, the papers encourage the principle of “cool first, transport second” because early, effective cooling reduces the risk of progression to severe heat stroke.^2,3

Editor’s note: An AI tool was used to aid in the author’s examination and summary of the research papers’ results.

References

1. AKC Canine Health Foundation. A Simple Solution for a Dangerous Problem. November 11, 2025. Accessed November 21, 2025. https://www.akcchf.org/educational-resources/library/articles/a-simple-solution-for-a-dangerous-problem/
2. Parnes SC, Mallikarjun A, Ramos MT, Stone TA, Otto CM. A randomized cross-over study comparing cooling methods for exercise-induced hyperthermia in working dogs in training. Animals (Basel). 2023;13(23):3673. doi:10.3390/ani13233673
3. Parnes SC, Mallikarjun A, Ramos MT, Capparell TR, Otto CM. Voluntary head dunking after exercise-induced hyperthermia rapidly reduces core body temperature in dogs. J Am Vet Med Assoc. Published online September 4, 2024. doi:10.2460/javma.24.06.0368