iPhone charger is hot

It should not be 'burning hot' - but, very warm is normal. My adapter has a surface temp (by IR thermometer) of 35-40 °C. Typical threshold for 'hot' pain is ~42 °C. Also, I'm connected to 110 V; the adapter does get a little warmer when connected to 220 V.

If it's truly hot, I'd recommend a call to AppleCare or a visit to an Apple Store.

Did you make sure to remove the clear pastic that peals from the charger? Don't do this while it is plugged in. The white cover is not to be removed. If there is nothing there that is clear that peals, it may indicate that you already have removed it. If it is removed and is that hot, you might have a bad adapter, or bad power in your home. Try to plug into an APC Surge protector or uninterruptable power supply (UPS). That will ensure you get the right amount of power. If it still is problematic, your machine is still under the 1 year hardware warranty. Be sure if you get a replacement power supply, that the service center/or Apple store is able to show you how to remove the clear plastic cover. Sometimes it is on there tight.

I just noticed the other evening that my charger became excessivly hot while charging my MBP. Almost too hot to hold in my hands. There is no cover on it, I had already removed that when I first purchased it. Not sure if that is okay or not.

Same here mine gets really hot too. I have a new MBP 15. I think it must be normal. I dunno. It isn't smokin' hot but very warm to the touch.

If the amount of heat is reproducible, change the outlet, try on an APC Uninterruptable Power Supply, and if still you think it is unusual, bring it in for service.

If additional issues happen that are not normal and related to power, ask to see if a replacement adapter makes a difference.

My adapter gets hot as well. Here is the answer... This simple add on lifts the adapter above any surface allowing it to dissipate heat more efficiently. Its just been developed and should be available in a few weeks. Its called PowerCurl and is available at
http://www.quirky.com/products/15-PowerCurl?r=6d3d0d519ae2407bcbb4374fc75d3c23
When not plugged in, it also doubles as a better cord wrap as well.

My adapter does not utilize a cord to plug into the wall. It is being used "wall wart" style. This gives it the maximum cooling possible. Nothing is wrapped around it to insulate it and keep it hot, nor is one face of it laying on the carpeted floor.

If your power adapter is charging your depleted battery plus powering your computer doing a very CPU intensive task then it will run much much hotter than if the battery is fully charged and you are merely surfing the internet or some other very low intensity task.

If it draws too much power, getting too hot, it will blow its own internal fuse. There is virtually nothing you need to worry about. One persons "way too hot" may be another persons "fairly warm".

If you want proof of that concept look at the thread about the sharp edges on the MBP. Some people are getting great pain from something that others do not even notice.