iwatch very hot when charging

Hi John

It is normal for your watch, power adapter and charging cable to become warm when connected to power.

If your watch experiences above-normal temperatures during charging, remove it from its charger, move it to a cooler place and let it cool down before putting it on or continuing to charge it.

Ensure also that you are charging it in accordance with the charging instructions.

More information:

Keep Apple Watch within acceptable operating temperatures - Apple Support

Check your battery and charge your Apple Watch - Apple Support

If you are concerned about a potential hardware issue, contact Apple Support or make a Genius Bar reservation with a view to having your watch and power accessories checked under warranty:

https://www.apple.com/support/watch/contact/