I am having the same issue with mine. I thought it was first an issue with the Linux kernel, but several kernel updates have come and gone with no one else reporting the issue. The ventilation on this model is exceptionally poor. I cannot use it for more than 20 minutes except on a desk due to the problem. I basically have a $1,000 paperweight.
I have always bought Dell, but this is pathetic. I love that the only answer given is useless garbage about cleaning air vents. So much for buying Dell in the future. Hopefully I can unload this on eBay soon and go buy a MacBook and load Mint.