CoolHands uses a phase-change material (PCM) with a 10 °C melting point to extract heat through direct skin contact. It can be applied to the hands or other body sites (such as the neck, forehead, or pulse points) to support local cooling and thermoregulation. It can also be placed on the chest and back for further regulation.

Heat extraction occurs by conduction and depends on a temperature gradient between the skin and the cooler material. While the PCM is solid or actively melting at its 10 °C set-point, it absorbs heat. Once fully melted and warmed toward skin temperature (typically the low-to-mid 30s °C), the gradient collapses, latent-heat capacity is exhausted, and the pack begins to act as an insulator rather than a heat sink.

Why the temperature range matters

• Too cold: Prolonged contact with a surface well below 0 °C can trigger strong local cutaneous vasoconstriction. This reduces blood flow to the skin, which may limit further heat delivery from deeper tissues and can become counterproductive to overall heat loss when core temperature is elevated (Alba, Castellani & Charkoudian, Exp Physiol 2019).
• Past the melting point: After the 10 °C phase change is complete, useful extraction ends. Leaving the spent pack in place adds thermal resistance instead of removing heat.

A 10 °C melting point provides a stronger, shorter extraction dose than milder 15 °C PCM grades used in longer-wear garments, while remaining above temperatures that commonly produce aggressive vasoconstriction or cold discomfort in most users. Placement on different body sites allows targeted use where local cooling is desired.

Practical guidance

Apply CoolHands while the pack is still active. Remove or re-chill it once it has fully melted and feels close to skin temperature - the same principle as not leaving a frozen pack in continuous contact beyond its useful window.

Wear time and storage

Lasts up to 2 hours, or throughout a shift if put back into a cold container. Store it in the CoolHed Portable Cooling Container, which fits 10, or in an esky.

Volume pricing

$85 AUD each, or packs of 10 to 1,000 on a volume discount with freight included in Australia. For more than 1,000, send a bulk enquiry.