Laptop CPU temp reaching 90 C

I have a Toshiba R630 laptop with Intel core i3 350M processor (the laptop is a very thin and light 13.3 model), under full load the CPU core temperature reaches 90 degrees, is this something to worry about?

That is rather hot. What is the idle temp? Have you cleaned your heatsinks and fans out of dust? How often do you load it like that?

50-55 is somewhat warm, but okay. Considering you have an i3 chip, I don't think a premium was placed on cooling when they designed it, so it's system is probably somewhat weak. I wouldn't worry, just keep the heatsinks clean and loadtime to a minimum. Really for loads like that, you should consider a performance notebook or a desktop computer.

I have underclocked it to 1.33 GHz and the temp under 100% load is now around 78-81 degrees, can this be considered "safe" ?

What are you loading the chip with?

Does the HeatSink even got Copper on it and since it's a mobile i3, I dont think it should be at 80s at all unless it's full aluminium heatsink... Look at the bottom and where the fan is at, cut and make the hole so more air can go through into the fan and ALSO cut the part where the air is going out so more air is going out...

I See, so it's just either Copper with 3-5 Copper Fins or Copper with 3-5 Aluminium fins OR It's just completely Aluminium... Just cut the part were the fan is sucking air and blowing air out...