How to say thermal cut-out

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I was wondering if anyone knows the technical term for thermal cutout or thermal cut-out in Spanish. This is a small electrical component used similarly to a fuse. When it heats up to a certain temperature, it cuts the current so the device won't overheat and cause a fire. I am in South America and I need to buy one to repair a power supply. Here's a picture of the one I need. Also, what would you call a store that sells electrical parts such as diodes and things- something like Radio Shack?

Thanks in advance.