Wrap it or enclose it in a good insulator, so that no heat
from the ambient 65°-75° can reach the snowball.
The best way to prevent a snowball from melting in a 24-hour period at temperatures of 65 to 75 degrees Fahrenheit is to keep it in a cooler or insulated container with ice packs or dry ice. This will create a cold environment to slow down the melting process and help preserve the snowball for longer. Avoid exposing the snowball to direct sunlight or warm temperatures to maintain its icy composition.