let's bring in dr. mark segal who has been following events several days now. let's talk about that. high-calorie liquid quiet. why? >> because they expected to become nauseous. they are under stress coming up to the surface. they want to be careful not to have them vomiting so they're using this diet nasa invented for astronauts to give them a lot of calories to get the energy, give them fluids. they have to replace fluids. they've been dehydrated down there. other point i want to make on the way up, viewers might say why are they worried about blood clots if it's only a 20 minute climb? the answer when you've been lying down there like this for months, when you stand up and suddenly up right that is when you might dislodge a clot. they're right to use compression stocks and aspirin. prevent blood clots, then deal with stress.