Bar mitts such as HotPogs (made in Nottingham) are absolutely fine on flat bars in windy weather, because they are cutting edge into the wind.
I'm 74 and have arms like twigs, so I would notice a problem.
I love my Hotpogs. I can add or remove other gloves and stash them inside the pogs. Mine have extra little pockets underneath for goodies, routesheets etc. Husbands have clear pockets on top for a map. I use them on and off road, and for MTBO events. As Fuadran says, if your hands do get too hot you can rest them on the tops as long as you know your road and aren't likely to need your brakes in a hurry. My hands are very clumsy due to arthritis, but I have no problems getting my hands in or out of the pogs quickly.
I did try a pair of mitts from another company, allegedly suitable for drop bars.
Well they fitted, but being broadside on to the wind, they made the bike unsteerable. Only used them once and binned them as dangerous.