When an animal cell is placed in a hypotonic solution

The hypotonic solution is that soultion which the amount of solute is in low concentration. If the cell is placed in a hypotonic solution then a cell fills up with water by the process of osmosis. This process starts to swells but the cell wall prevents the cell to get burst, which is the natural process within the animal cell. The pressure inside the cell increased until the inter pressure is equal to the pressure outside the cell.

your body is trying to warm itself up. or more precisely, sensors in your skin send messages to your brain to generate heat to your body.