My atomizer is getting really hot, is this normal?

It is normal for the atomizer to feel warm or hot to the touch. If however it is so hot that you are unable to touch it, you should start by checking the coil. An accumulation of gunk on the heating coil will produce a lot of heat and very little vapor.

If the problem is a build-up of e-juice aka gunk, consider that the Propylene Glycol (PG)/Vegetable Glycerin (VG) ratio of your e-juice might not be the right fit. Vegetable Glycerin has a consistency similar to syrup hence the more VG an e-liquid contains the thicker it is.

You will need to give your atomizer a deep clean and/or replace the coil.

If your atomizer is still overheating after a good clean, your method of vaping may be the issue. Chain vaping can lead to your atomizer's inability to replenish your e-juice fast enough, resulting in a damaged coil and diminishing flavor. You can solve this issue by taking a break from your e-cigarette. As little as 5 - 10 minutes should be sufficient to allow your atomizer to replenish and your wick to re-saturate itself.