I am thinking of getting my husband one of those heated vests for Christmas.  He works outside and thought it would be nice.   Wondering if anyone had ever purchased one. I have Googled until I am cross-eyed !!!     I think he would prefer the thinner one to wear under his hoodie so it wouldn't be real bulky for him.  Any and all thought and opnions will be greatly appreciated. 

Hubby ordered 2 for us, cant wait to get them to see how they work out. They should be here any time, but of course its warmed back up so have to wait for another cold front to come in to get to try them out.

They are amazing!  My husband, Dad, and myself all have the one below, but an older version without the bluetooth (we got them at the star of last winter).  I just ordered socks from the same company that should be in Monday.

https://mobilewarming.com/collections/mens-vests/products/vinson-vest-men

You want to make sure it's close to your skin (under a hoody like you suggested is great) and it really does best with a coat/hoody over it to hold the heat in.