Could a heatwave make World Cup matches 'unsafe' this week?

Could a heatwave make World Cup matches 'unsafe' this week?Image source, IMAGN IMAGES/ReutersByDarren Bett and Simon King , Lead Weather PresentersPublished13 minutes agoTemperatures will be rising in parts of the United States and Canada this week as dangerous heat builds, according to the National Weather Service (NWS).The heat will be accompanied by high humidity which will make the weather more uncomfortable with possible health-related impacts.As the heatwave intensifies later this week, heat indexes may approach the threshold where Fifapro consider it too unsafe for play.This means that some of the World Cup last-32 matches this week could experience some of the hottest and most difficult conditions of the tournament so far.Image caption, Western areas have seen temperatures dropping a heatwave is developing further eastA large heatwave will intensify as the week progresses covering much of central and eastern US states and through much of Canada. Temperatures in excess of 32C (90F) are widely expected.But, add in the humidity, it will actually feel like temperatures are up to 46C (115F) across portions of the southern Plains, mid-Mississippi valley and eventually into parts of the Mid-Atlantic, according to the NWS.Overnight temperatures may not fall below 20C (70F) - classed as 'tropical night' by meteorologists. The extreme heat will also affect eastern Canada with temperatures forecast to be up to 10C (18F) above average in Ontario and Quebec.Which matches will be hot?Not all of the Round of 32 matches in the World Cup will be affected by the heatwave but there will be some notable games to keep an eye on.The hottest weather this week will be in Texas which will mostly impact fans travelling to and from the air-conditioned stadiums in Houston and Arlington.In Houston for Brazil v Japan on Monday the 'feels like' temperature will be around 44C (111F) and in Dallas on Tuesday up to 41C (106F). It will obviously feel much more pl...