In pictures: Mercury rising

1 of 5 Olga Born, 23, and Marina Schmidt, 24, from Germany, chill out in London's Green Park

2 of 5 The MacLeod Family from San Diego take time out from a visit to Westminster Abbey in London

3 of 5 A squirrel is fed a peanut in the shade of St James's Park

4 of 5 Eight-year-old Oliver Chard from Bath cools off in the fountains at London's Trafalgar Square

5 of 5 Nivea handed out free sunscreen to people sunbathing in Soho Square, London