A heatwave is likely to hit North Devon tomorrow (Tuesday) with the hottest day of the year so far expected. The Met Office has issued a level two heat health warning with an 80 per cent change of heatwave conditions until Thursday. Temperatures are likely to build throughout tomorrow and into Wednesday. A spokesman for the Met Office said: There is still some uncertainty regarding peak temperature values on these two days, however the highest maximum temperature is expected on Wednesday. Confidence in warm and humid nights to end Tuesday and Wednesday is currently much higher. A final area of uncertainty is the longevity of the episode, with temperatures currently thought likely to moderate from the west on Thursday as the warmest air gradually transfers eastwards. Heatwaves can be dangerous, especially for the very young or very old or those with chronic disease. Advice on how to reduce the risk either for yourself or somebody you know can be obtained from NHS Choices at www.nhs.uk\/summerhealth, by calling 111, or from your local chemist.