(Redirected) Laptop Runs Too Hot - Latitude 15 5000

We've recently purchased 6 Dell machines. 3 of which are Latitude 15 5000 with the Intel core 5 processors.

When we got the new laptops, we immediately switched the OS to Ubuntu for the latitude machines. Two of them run completely fine, but one of them is running unusually hot.

It takes only about 5 minutes of regular use to reach the point where the laptop is uncomfortably hot. We've checked the running processes (with "top" command) and there doesn't seem to be anything unusual.

Anyone have suggestions on what we may be missing. Thank you.