Dog owners have been warned to beware a "silent killer" that could endanger their pooches as the UK is set to reach 34C highs this week.
Parts of the South East, London and Wales could reach at least 27C, rising to a possible 34C on Friday, hotter than Portugal, Jamaica, Costa Rica, the Canary Islands and Cyprus.
Friday is also predicted to be the hottest day of the year so far, eclipsing the 27.5C set in mid-May at Heathrow. It could even be the hottest June day for the UK since records began if the mercury tops the 35.6C recorded in Southampton in 1976.