As another bout of sweltering heat is set to hit Massachusetts, the MBTA is alerting riders that the extreme heat could cause delays on the commuter rail on Friday.

Boston is facing a heatwave with temperatures potentially breaking records, reaching the 90s today and near 97°F tomorrow.

On a southwest wind, temps snuck up to around 90 yesterday, and today, we’ll head into the mid 90s. The record for the date

The past few days have featured near or slightly cooler than average temperatures. By Thursday, though, the sea breeze will hold off and temperatures are expected rise into the low 90s.

Our team coverage of Friday’s weather continues with a look at how workers dealt with the extreme heat, especially those at pizzerias.

The blast of heat prompted advisories across much of Massachusetts, Rhode Island, Connecticut, and in Southern New Hampshire and Maine.

The heat index, or how it feels with humidity factored in, will rise into the triple digits for millions as the hot dome of high pressure engulfs the central and eastern states.