MH
Michael Harrington
Systems, engineering, analytics, and applied strategy
At a Glance

Summary

The short version: what DuraTherm is, what the test showed, and who it is for.

Typical gel pack and DuraTherm pack in infrared

DuraTherm at a glance

What it is. A patent-pending cold pack filled with cotton-reinforced ice instead of chemical gel. It is based on Pykrete, a fiber-ice composite proven since World War II.

What it does better. It keeps an even cold across the whole pack and warms more slowly than standard gel packs.

0 of 23DuraTherm packs ever reached the 70°F out-of-range line
10 of 27standard gel packs were at or above 70°F at the 5:00 a.m. read
½ the rateDuraTherm warmed 0.86°F per hour vs 1.68°F for gel packs (3:00–5:00 a.m.)
2.8°F colderaverage surface at 5:00 a.m.: 66.7°F vs 69.4°F
Uniformity. Across 40 measurement rounds, DuraTherm demonstrated approximately 53% greater pack-to-pack temperature uniformity than conventional gel packs, with lower temperature variation in every round.
Infrared images of a typical gel pack and a typical DuraTherm pack at 8:45 pm on the same temperature scale
8:45 p.m., about six hours out of the freezer. The typical pack of each type (the median of 27 gel packs and 23 DuraTherm packs by center reading), shown on one shared five-color temperature scale. The gel pack has a single cold pocket and a warm body; the DuraTherm pack is cold across its face. Group center readings at this time averaged 45.1°F for gel packs and 40.9°F for DuraTherm.

The proof

A 14-hour infrared test of 62 packs, side by side in the same shells and the same room. The medium packs carried the main comparison: 27 standard gel packs against 23 DuraTherm.

Standard gel pack (27)DuraTherm (23)
58 60 62 64 66 68 70 72 Average surface °F 1:30 2:00 2:30 3:00 3:30 4:30 5:00 Read time, Oct 4, 2026 (a.m.) 70°F out-of-range line Gel pack, 1:30 a.m.: 62.8°F Gel pack, 2:00 a.m.: 62.5°F Gel pack, 2:30 a.m.: 65.6°F Gel pack, 3:00 a.m.: 65.7°F Gel pack, 3:30 a.m.: 67.9°F Gel pack, 4:30 a.m.: 68.8°F Gel pack, 5:00 a.m.: 69.4°F ● Gel pack 69.4 DuraTherm, 1:30 a.m.: 60.3°F DuraTherm, 2:00 a.m.: 63.0°F DuraTherm, 2:30 a.m.: 63.8°F DuraTherm, 3:00 a.m.: 64.3°F DuraTherm, 3:30 a.m.: 66.9°F DuraTherm, 4:30 a.m.: 66.5°F DuraTherm, 5:00 a.m.: 66.7°F ● DuraTherm 66.7

Average whole-face surface temperature of the 27 gel packs and 23 DuraTherm packs at each overnight read. The dashed line is the 70°F out-of-range line. Hover a point for its value.

  • Warming rate after 3:00 a.m.: 0.86°F per hour for DuraTherm vs 1.68°F for gel packs (p < 0.0001).
  • Surface at 5:00 a.m.: 66.7°F vs 69.4°F (p = 0.0001).
  • Evenness across the pack face at 5:00 a.m.: 0.84°F vs 1.19°F spread, about 30% more even (p = 0.0001).

Who it is for

  • Medical cooling: injury care and before or after surgery, where skin-safe, even cooling matters.
  • Pharmacy and medical shipping: mailed medications and biologics that must stay cold in transit. A single-use version for pharmacy shipments is in development, aimed at the VA.
  • Food delivery: parcel-size cold chain.
  • Sports, fitness and recovery.

DuraTherm does not target truck or trailer-load cooling.