With temperatures soaring as high as 37°C in St Albans and Harpenden this afternoon, here are some of the places you can go to cool down.
The Splash Park at Verulamium Park in St Albans is open until 6pm, and includes both high and low water features suitable for children aged 12 and under.
All visitors who will be running through the water are required to wear swimming garments, and ice cream and cold drinks are available.
There is also a paddling pool at Morris Way playing fields in London Colney, with a walk-in shallow end and steps into a deeper end (about one metre).
To avoid being outside altogether, the swimming pool at Westminster Lodge Leisure Centre in St Albans is open until 10pm on Thursdays.
The Holywell Hill centre has three pools; a water confidence pool with slides and fountains, a teaching pool and a 25m pool with 10 lanes.
In Harpenden, the swimming pool at Harpenden Sports Centre in Rothamsted Park is open for lane swimming until 2pm, and again from 6.30pm to 10.30pm.
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