When it is winter in the Northern Hemisphere, the Southern Hemisphere faces the Sun more directly and thus experiences warmer temperatures than the Northern Hemisphere. Meaning that the date is June 21- summer
Land animals require more energy since they have to overcome greater inertia during locomotion. Land mammals have adopted many evolutionary mechanisms to support high energy demand.
Heart is four chambered instead of the usual two in aquatic animals like fishes. More number of divisions in heart increases the efficiency of blood circulation process which in turn increases the oxygen delivery rate to cells for producing more energy.
Land mammals also have developed lungs which increase the efficiency of gas exchange process which increases the output of respiration process.
In addition, land mammals also have a strong and developed musculoskeletal system which helps in locomotion.
When you do that the fish will die. That is because it will take too much water in it and die from it, or rather, the fish's cells will take too much water in.
