The first thing you have to worry about is feeding him.
To generate that much heat, he has to be getting the energy from somewhere. Let's assume that he metabolises energy the same way we do; through food. The average human consumes around 8700Kj to maintain a body temperature of around 37oC, in environments that average around the 25oC mark. Note, this is a MASSIVE simplification, but will help with rough order of magnitude figures.
That means that every day, the human body is using around 725Kj per degree C to maintain the differential. When we do the math, let's make it easy on ourselves and say that the average body temperature our hero maintains is 325oC, or 300o above room temperature. That means that our hero would need to consume 217,500Kj of food each day. He's going to spend all his time eating, and that's not the half of it; he's going to need massive lung capacity to metabolise the food with oxygen, and his biggest problem is going to be getting enough water given that it's going to flash boil as he tries to drink it.
Another problem that you have is that trying to insulate yourself so you can touch others is a REALLY bad idea. With that kind of warm blooded metabolism, even some form of lead lined insulative clothing including shoes and gloves is only going to amplify the problem in that the body can't dispel the heat through normal convection. That means that your body temp is going to climb rapidly, potentially melting down the insulative material and overwhelming it.
Even if he did find a way to have a meaningful and intimate relationship, he can never father children. I always wondered why (not to be indelicate) something as sensitive on the male body like testes were put out in the open so to speak, rather than being more protected inside the body. That is, until I read that male sperm is actually quite sensitive to normal body temperatures and actually start to die off at 37o; presumably this is so that women can't ovulate and be fertilised by 'old' sperm that may have degraded - you only want the fresh stuff. The scrotum is in effect providing a heatsink for them to keep them cool. The problem is at these temperatures, your hero is effectively sterile regardless.
But for the sake of argument...
Ultimately, the best thing your hero could do is go angelic; Imagine a thermal suit that efficiently takes the heat out to a massive heat sink array on his back that would effectively look like metallic wings. This might allow him to touch people with his hands or be around people to his front, with massive heat radiating out from behind him instead.
This would have two practical benefits; the first is that he could have meaningful conversations with friends in a circle around him so to speak, but it would also prevent anyone from ever sneaking up on him from behind.