Charvis, speaking from the Wales squad's gruelling warm weather training camp in Lanzarote, says for the players it's a question of survival during the intensive training sessions from now until the tournament in Australia.
"We still don't feel like we are at the world cup, we need to get the next two weeks out of the way, put the hard work in and get on that plane to Australia, then it will start to feel different," said Charvis.
"We've got a lot of hard work to do with something like 6hrs of training a day, but if we want to compete with the best in the world we have to put ourselves through that kind of regime.
"It's a question of survival for us this week, it's not too hot at the moment but its going to get hotter.
"We are in a fairly desolate place in the middle of nowhere, not the sort of place you'd want to come to on holiday - the island is basically a big volcano."
On the subject of his recent appointment to lead the side for the world cup Charvis added:
"The captaincy has not really been an issue for the squad, it has changed hands fairly regularly recently and we have lots of leaders in the side."