Children especially should have sunscreen with a minimum protection factor of 15, applied 15-30 minutes before going outside and reapplied after swimming.
The Met Office works closely with the Department of Health to produce the Heat-Health Watch.
This is a warning to health professionals to help minimise risks to public health, particularly of the elderly.
The Met Office has warned of the increased risk of temperature thresholds being reached this week.
But the heatwave has a long way to go to match 29 years ago.
The highest temperature recorded in Huddersfield in recent times was back in the summer of 1976, when in July it hit a high of 31.8°C - which is above 90°F.
