Page 99 - Mike Murphy's Blog Posts

More importantly, by reducing the skin temperature, you can apply higher fluences without causing excess pain or tissue damage. As I said above, with a few minutes ice cooling I was able to tolerate 40 J/cm2 easily on my skin. I seriously doubt many people could tolerate that level of fluence without cooling!
Many devices use cold tips which also help to cool the skin. While this is true, many of these tips will warm up during treatments. That’s because the device’s internal cooling system is not powerful enough to keep the lamps or diodes cool, whilst also keeping the skin cold.
My advice is to regularly check the temperature of your device’s tip on your own skin during treatments. If it feels ‘warm’, stop the treatment until it cools down. This may take a minute or two (depending on your room’s air temperature!!)
Post-cooling
I have calculated that many laser/IPL treatments ‘waste’ around 90% of the light energy! Less than 10% of the energy we fire at the skin actually does the job were trying to do. This is due to loss of light energy due to back-scattering (out of the skin altogether), absorption by other tissue components and transmission through the dermis.
As a direct consequence, most of the light energy that remains in the skin will be attempting to heat up other tissues, such as the collagen. We must deal with this excess heat energy quickly, before any damage is done.
The most efficient way is to apply ice packs immediately after an area has been treated. This will draw out the excess heat quickly and significantly reduce the risk of unwanted skin damage.
I recommend cooling the skin for at least five minutes after each treatment to ensure proper cooling.
Summary
When we treat hair, vessels or pigmentation we are deliberately inducing a temperature rise in the skin. But this must be a highly controlled temperature rise. It must be ‘balanced’ with sufficient cooling to prevent unwanted thermal damage.
If you increase the fluence applied to the skin, you must also increase the skin surface cooling commensurately.
If you don’t cool sufficiently, you run a much greater risk of damaging tissues such as the epidermis and/or collagen. You are also limited to using lower fluences to reduce pain.
Mike’s Blog Posts 99