In the article it says go to see the doctor if you experience two weeks or more of regular night chills and sweats.
I'd add that if you are experiencing them every single night and if they seem quite sudden and severe, just go and see your doctor as soon as possible.
This is especially true if you have other symptoms like headaches and stomach pain.
And remember to drink a lot of water. You might not realize how much fluid you are losing each night and dehydration is only going to make you feel worse.