#Assuming both people thermoregulate, no problem

Mammals and birds are endothermic, meaning that they create the heat they need to maintain their body temperatures inside them. Since they require a specific body temperature to live, these animals must also be able to cool themselves.

For the Hot-heads, heating themselves should be no problem. If their body maintains its own body temperature, then all they have to do is wear a polar bear-worth of skins and they should be fine. Their body will generate heat as needed until it is at the correct temperature.

The Ice-queens will have a bit more trouble, depending on how cold they need their internal body temperature to be. Human body temperature is around 37 C, which is generally hotter than the daily average temperature anywhere on Earth. Humans are almost always able to shed heat to the environment because the environment is colder than their body. Humans also sweat to drop the extra heat.

The Ice-folk probably won't be able to sweat; since their typical environment is below freezing sweating wouldn't do much good. I would assume that applying ice/snow to themselves would be their preferred method of cooling down and maintaining their preferred body temp.

Therefore, in order to meet each other, the people should interact in a cool enviornment more suitable to the Ice-kins, and the Hot-ites need to bundle up.