Public Health England has warned this week's heatwave in the South East could have a "significant effect on health".
The Met Office has declared a level 2 heat-health alert. It's activated when there is at least a 60% chance of temperatures being high enough on at least two consecutive days and into the night to have a impact on health.
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Industrial vacuum cleaners and magnetic wands will be used each night during the summer to remove metal particles, dust, oil and grease.
Detective Superintendent Fiona McCormack said the Hotpoint FF175BP model had not been subject to any product recall.
Security for this year's event on July 8 has been reviewed following a spate of terror attacks in the capital.