Macbook Pro high temperature = reduced lifespan?

So I bought my retina MBP to be portable, but it turns out I usually just leave it on my desk plugged into two monitors.

I use a lot of intensive software so the temperature usually sits at 70 celcius for the CPU and 80 celcius for the GPU. Are these constantly high temps going to reduce its life? Am I better to sell it and buy an iMac? Or will it be fine?

Thanks