Temperature on the slate is not THAT hot. I hold it whilst painting and Ive NEVER EVER needed to remove my hand because of it being to warm. I've been drawing in Cafe's and Malls with the Slate on my lap and again..NEVER too hot.
Yes it's idle around 50c but that's not what is transmitted to the surface ...god no, that would be dangerous. It does not affect the performance nor does it affect painting workflow. Maybe andya147's slate had an issue or maybe you've been out in the sun with the slate