LOS ANGELES (AP) — The World Cup games are heating up this week with knockout rounds, and so is the outdoor heat.

A dangerous heat dome will engulf the central and eastern U.S. this week with heat index temperatures — which combine air temperature with humidity — soaring into the triple-digits in some areas. Conditions will bring above-average temperatures to World Cup host cities such as Boston, Philadelphia and Kansas City, Missouri, all of which have open-air stadiums.

The Associated Press