Brain Freeze instantly freezes an entire waterpark at once.
Second picture to prove the waterpark was indeed frozen.
Traditional water parks carry about 900,000 gallons of water in them.
900,000 gallons weighs 3,406,870.61kg
(taken from http://convert-to.com/conversion/water-weight-volume/convert-us-gal-of-water-volume-to-kilogram-kg-of-water-weight.html)
Latent heat of water is 334,000 J
3,406,870.61 * 334,000 = 1,137,894,783,740 J
=
271.9633804349904267 tons of TNT; well into Multi-City Block Level.
And that doesn't count all the snow, the fact that he also froze the water in the hot tub, or the blocks of ice he froze each of the plants in.