Britain could see a dramatic increase in food poisoning cases and waterborne disease as the warmer, wetter weather linked to climate change takes hold.
Will people have more barbeques in the hotter summers?
Hotter summers could lead to more salmonella cases as people opt for more barbecues but leave food out of the fridge, Professor Paul Hunter warned.
Heavy rain may also lead to more cases of diarrhoea-inducing cryptosporidium.
The University of East Anglia expert said Britain may also see some malaria cases - but is likely to cope.
This is because unlike most areas of the world badly affected by the disease, Britain has a public health system which could tackle any outbreaks, he said.
Professor Hunter said: "It's fairly accepted that most of the changes are going to be around hotter summers and more frequency heavy rainfall.
"We already know that food poisoning is related to temperature. This is because if you leave food outside the fridge at warm temperatures germs grow."
If people did not change their behaviour, and continued to leave food out at the hotter "ambient temperatures", food poisoning was likely to cases were likely to increase, he said.
"There's an interesting area around climate that's how is it going to impact on human behaviour - people have more barbecues when it's hot."
Poorly cooked meat on home barbecues has long been associated with food poisoning.
Professor Hunter also warned that heavy downpours could lead to an increase in outbreaks of the water-borne bug cryptosporidium which causes diarrhoea, vomiting and stomach cramps.
This was especially likely in the "periphery of water supply", such as in farms and holiday cottages, where water facilities were not supplied from the main network," he said.
"There's still an unbelievably high proportion of people that drink private water supplies.
"There's evidence to show that these particular supplies are very susceptible to heavy rainfalls."
He also warned that people swimming in the sea could be more likely to suffer from diarrhoea as recreational water supply becomes increasingly affected.
This was likely to be through muck being washed off fields, onto roads, into rivers and into the sea, rather than by the sewage that has previously caused problems.
Professor Hunter also warned that higher temperatures may lead to a few cases of malaria before the end of the century.
But he said that unless the UK suffered a severe economic crisis, the public health system would be likely to cope.
Gordon Nichols from the Health Protection Agency's Centre for Infections agreed with Professor Hunter's analysis of the risks.
But he added that there may also be an impact on the kinds of disease Britain sees in the future as a result of migration sparked by climate change.
Flooding in huge areas of Bangladesh for example could lead to huge population movements.
He also said the impact of Britons travelling abroad should not be underplayed.
"The fact that the impact of climate change here isn't very big doesn't mean that we won't get diseases from people travelling abroad," he told the BBC News Website.
Professor Hunter's comments come the day before a major conference on epidemiology and vaccines at the Royal Society in London.