Hi there! Do you know what happens when you go out in the sun and feel warm on your skin? That's because the sun gives out something called light and heat. Photothermal therapy works like the sun, but on a much smaller scale.
There are tiny things called nanoparticles that can be put in your body. They are very, very small, so small that you can't see them without a very big microscope. These nanoparticles are made of special materials that can absorb light, just like your skin does when you are out in the sun.
When these nanoparticles are put into your body and light is shone on them, they get hot. And when they get hot, they can kill the bad things that are making you sick, like cancer cells.
So, photothermal therapy is when doctors use these tiny nanoparticles and light to kill bad things in your body, without hurting the good things. It's like a secret weapon that helps your body fight off sickness!