Lt. Gov. Timothy Murray is recovering from the effects of extreme heat after marching in five parades over the July Fourth weekend.
Spokesman Kyle Sullivan said Tuesday there was no change in Murray's condition.
Sullivan said Murray decided to seek medical attention Monday evening and checked into St. Vincent Hospital in his hometown of Worcester. Weekend temperatures peaked at over 90 degrees.
The Democrat celebrated his 42nd birthday last month. The former high school quarterback has exhibited no other health problems since taking office in 2007.
Murray and Gov. Deval Patrick are seeking re-election this fall.
They are running against independent candidate Timothy Cahill, Republican Charles Baker and Green-Rainbow Party candidate Jill Stein.