Lettuce be Thankful?

I must admit to not being too enthusiastic about the green stuff but, in the current heat-wave, UK lettuce prices are reportedly rocketing (get it?) as the local crops have failed to cope with the elevated temperatures and water shortages (https://www.theguardian.com/environment/2018/jul/13/uk-imports-salad-from-us-spain-and-poland-as-heatwave-hits-crops). Demand (it's hot, so lets eat salad) has, reportedly, led to lettuce being imported mainly from the US, Poland and Spain. Wasn't it only a short time ago when lettuce was linked to E. coli outbreaks? I do hope that the imports are being carefully monitored.