The last thing I ever want to do with one of my heaters is turn it off completely, by accident. Bad things might happen to my house in February if I do that. There’s a reason that thermostats don’t usually have an off switch on the faceplate.
And yet there’s a small button on the HA dashboard that does exactly that. Can this button be hidden?
This is not an answer to your question but you could create an automation that turns it on if it got switched off.
Simple thermostat is highly configurable.
You could also make your own cards with horizontal and vertical stacks.
Mine look like this.
Maybe with CSS
Thank you all. I didn’t realize it was relatively easy to swap out the interface like that. I’ll look into it.
I also really like the suggestion to simply have an automation to turn it back on if it gets turned off. Might be easiest!
But hardly intuitive. People may keep hitting the button if they really want the heater off.
Put a delay in first, so it will wait 5 minutes before turning it on again. 
That is without a question!
It is a simple script with a service call to turn it (and maybe a delay first to prevent a stubborn user) and then an automation to trigger the script.
Since the only user is me, I think I’ve got that part taken care of. 
And if I forget, then I deserve the frustration!
If you are the only user, how is it a problem anyway?
On a mobile device it’s easy to click when scrolling.
Since I went to the school of s happens when to you least want it to. I’d do 3 things