Reading the news it said you could use 6 daily ice creams during the heatwave in case you still wanted to get those titles. I used 3 and I get the brain freeze message.
After eating one icecream on the 26th at 09:03 BST I got the message that I could eat 5 more icecreams.
As the heatwave started yesterday at midnight you should have been able to eat 6 icecreams at time of posting... I suppose then it must be members-only. :/