Hi, we get asked this question a lot so I though it best to write a post on the topic. There is no easy answer to this but I will finish up with some examples. The question is not how cold does Physicool get? After all, the benefit of cooling an injury in not to reach a certain temperature, the aim of cooling is to treat pain and swelling caused by a trauma and to promote healing and recovery. Physicool uses evaporative cooling which draws heat out. The heat then leaves the body/skin and evaporates away. So the question should be; How much heat is present that you want to remove?
The temperature that Physicool cools will depend on the amount of heat within the bandaged areas. As an example, a knee becomes very hot and inflamed following invasive surgery. Physicool draws heat out from the hottest part – the injury. The evaporative process actually feeds on heat, pulling heat out of the covered area. This is unlike ice-based treatments where a 0 degrees application is applied directly to the skin’s surface. In this case the cooling needs to penetrate down to the injury to give benefit. Normal skin temperature is +/-33 degrees.
A easy metaphor to help explain the difference is the comparison on how an air conditioning unit cool (sucking heat out) compared to refrigeration. One of the reasons Physicool has proven to outperform ice-based treatments is because it draws heat out from the hottest source rather than having to penetrate from the skin’s surface level down to the injury.
Physicool studies measuring temperature (in centigrade)
1. This study uses a thermographic camera to measure a difference of over 10 degrees – https://www.physicool.co.uk/pages/physicool-the-science-how-physicool-works
2. Two other studies where undertaken in Italy using infrared thermometers. The outcomes measured a 7 degrees and 21 degrees differences.
Both thermoimaging and infrared thermometers have their limitations. Both devices measure the surface temperature and any temperature change. However, these surface temperatures are reactions to a sub-surface activity.
If anyone reading this is friendly with a physiologists I would love them to measure the efficacy of different cooling systems and how they influence healing. I have spent hours researching this topic and there is very little evidence. It would make a great project. In my opinion, the best method of telling how effective any cooling device will be at cooling and influencing healing would be by injecting small thermometer cells into soft tissue at different distances from the skin’s surface. The thermometers should be able to indicate how effective different devices are at cooling soft tissue at different sub-surface levels. This however throws up another question. What is the optimum temperature and length of cooling needed to promote healing? I bet you it is not 0 degrees for 20 minutes. Interested? please get in touch.
Some injuries can be self-treated whilst others require prompt medical attention. You should seek advice from a health professional if: the injury causes severe pain, swelling, or numbness; you can't tolerate weight on the area; the pain or dull ache of an old injury is accompanied by increased swelling or joint abnormality or instability.