Both Bjorn Lomborg and Freeman Dyson advance this argument.

It's typical of so many denialist arguments - superficially true but a furphy

The bottom line is that this argument appears to argue that somehow AGW is a good thing because it will lead to fewer deaths.

It's a gross misrepresentation of what actually happens

More people have ALWAYS died in the winter than in the summer (they are more vulnerable then) but AGW won't change that - what it will do is lead to more extremes - especially in the summer.

here's a simple rebuttall

http://www.lomborg-errors.dk/coolitBchap2heat.htm

By the way I tired to link this to the Freeman Dyson argument on the deniers page but for some reason the link wouldn't work