The answer to 'panel upgrade gets hot' is that a hot electrical panel is often a sign of an underlying issue that requires professional attention. Common causes include overloaded circuits, loose connections, aging components, or improper wiring. Symptoms may include the panel feeling hot to the touch, breakers tripping frequently, or visible signs of overheating.
While some basic troubleshooting can be done, it's generally best to have a licensed electrician inspect the panel and make any necessary repairs or upgrades. DIY work on electrical panels can be extremely dangerous if you're not properly trained, so it's important to call in a professional if you notice any issues with your home's electrical system.