The hottest day of 2009 so far has been recorded as a heatwave descends on Britain.

The hottest day recorded in the UK so far this year was Monday 29 June when temperatures reached 30.4 degrees Celsius, however this is likely to increase to 33 degrees by mid-week.

The last time temperatures were recorded at such levels was in 2006, and the first Heat-Health warning has been issued by the Met Office.

The Trades Union Congress (TUC) has urged employers to consider the effects of excessive heat, in particular for those employees who work outside. It states that employers have a legal obligation to protect employees, and can implement different working shifts, offer protective clothing and sunscreen to help minimise risk of skin cancer and other sun-related ailments.

The Local Government Authority (LGA) has warned that each one degree in temperature rise results in 75 extra deaths every week – and reached a total of 2,000 extra deaths in 2007.

Cllr David Rogers, Chair of the LGA’s Community Wellbeing Board, said: “Councils are determined to reduce the toll as much as possible, but they cannot do it alone. Local people can make a massive difference by helping us identify other residents who might need some advice or practical help.

“No-one’s immune to the power of the sun. Looking around at how our older neighbours are coping as we walk our children to school or head to the beach for a day out takes no effort, but could be crucial in making sure they are also able to make the best of the summer.”

Tips to help combat heat include: drinking plenty of drinks (avoiding caffeine and alcohol); placing bowls of water around the house as evaporation helps cool the air; and avoiding the direct midday sun.

Head of Health Forecasting at the Met Office, Wayne Elliott, said: “The Heat-Health Watch is currently at level two, with the probability of heatwave conditions at 70%. We expect this to increase to level three during the course of the week.”

Temperatures are expected to drop momentarily for the coming weekend.

Those concerned about health during a heatwave are advised to contact NHS Direct on 0845 4647, or their GP or pharmacist. For further information about the heatwave and the measure in place within England, read the Department of Health’s Heatwave Plan.