Temporary - How to convey heat?

Holiday just after Xmas at southern beach and river resort. Starting to warm up to another spell of 40C plus days. Todays temp in Adelaide is going to be 43C.

A bit difficult to convey the oppressiveness of days of 40C plus - definitely restrict activities and try to find a cool spot. Seas lovely and cool but beaches are not all that cool and somehow showing people playing in the beautiful clear waters with lovely blue skies doesnt convey the whole message.