Finance Minister Heng Swee Keat, who suffered a stroke yesterday, had been shouldering an "incredible load" as a key figure in the Cabinet.
In a Facebook post yesterday, Prime Minister Lee Hsien Loong described him as a "valuable member of my team".
Deputy Prime Minister Tharman Shanmugaratnam called Mr Heng "one of Singapore's finest sons, and a leader with much promise".
Home Affairs and Law Minister K. Shanmugam pointed to the heavy workload Mr Heng was shouldering, which included charting a path for the country's economic future.
In a Facebook post, Mr Shanmugam noted that Mr Heng "was carrying an incredible load, handling the Finance Ministry, various important projects, including SG50, and the Committee for Future Economy (CFE) - this Committee has the crucial task of charting our economic future". He said he could see that Mr Heng "was very tired", adding: "I have been telling him that he was overworking so much that it will affect his health."
PRAYERS WITH HIM AND FAMILY
Heard the news about Minister Heng Swee Keat. Hope he has a speedy recovery. Our thoughts and prayers are with him and his family during this difficult time.
LEADER WITH MUCH PROMISE
Let's hope and pray for Heng Swee Keat, who is being treated in hospital after suffering a stroke during a Cabinet meeting late this afternoon. He is one of Singapore's finest sons, and a leader with much promise.
DPM THARMAN SHANMUGARATNAM
BOLD IDEAS FOR ECONOMY
Swee Keat has had a close association with the banking industry, both through his role as MD of MAS and now as Minister for Finance. His ideas for transforming the future economy of Singapore are bold, and we wish him a speedy recovery.
DBS CHIEF EXECUTIVE PIYUSH GUPTA
APPEARED VERY TIRED
Have been working closely with Swee Keat on a number of things. I could see that he was very tired. I have been telling him that he was overworking so much that it will affect his health. He was carrying an incredible load, handling the Finance Ministry, various important projects, including SG50, and the Committee for Future Economy - this committee has the crucial task of charting our economic future. Praying for him.
LAW AND HOME AFFAIRS MINISTER K. SHANMUGAM
WISH FOR SPEEDY RECOVERY
We wish Minister Heng Swee Keat speedy recovery.
STATEMENT BY THE WORKERS' PARTY
SADDENED BY THE NEWS
The Singapore Democratic Party is saddened to hear that Minister Heng Swee Keat has suffered a stroke. We would like to wish him a speedy recovery. Our thoughts and prayers are with him and his family.
STATEMENT BY THE SINGAPORE DEMOCRATIC PARTY
A key member of the fourth generation of leadership, Mr Heng joined the Government after the 2011 General Election and helmed the weighty Education portfolio before moving to Finance in the new Cabinet formed after the 2015 General Election.
Dr Gillian Koh, the Institute of Policy Studies' deputy director for research, said: "Mr Heng has made valuable contributions not only to the Government, but also to many in society, like the business groups.
"They would recognise his contributions to their lives and certainly look forward to more of that."
Mr Heng delivered his maiden Budget statement in March, which observers said provided boosts for small and medium-sized firms in an uncertain economic climate. And as head of the CFE, he is responsible for looking into Singapore's next stage of economic development.
Mr Heng was in Frankfurt, Germany, last week to attend a three-day meeting of finance ministers and central bank governors of Asean, China, Japan and South Korea.
Mr Liang Eng Hwa, who chairs the Government Parliamentary Committee for Finance and works with Mr Heng, said that despite his busy schedule, Mr Heng "made every effort to attend engagement functions organised by both business leaders and the grassroots, to know the ground better".
Observers have said Mr Heng was earmarked as a potential prime minister from the start.
After he was elected, he was immediately appointed a full minister - only the second time a new MP had been catapulted straight into Cabinet. He was also given other high-profile appointments on top of his heavyweight portfolios.
Last year, he headed the steering committee that oversaw the SG50 Jubilee celebrations. He also led the year-long Our Singapore Conversation series of dialogues in 2013.
Within the People's Action Party, he was one of two fourth-generation leaders given key roles after last September's General Election. PM Lee tasked him with analysing the party's GE2015 performance, and he was also alternate chairman of the party headquarters' executive committee.
Mr Heng is the anchor minister for Tampines GRC, chairing monthly GRC meetings and the advisory board for an upcoming sports and lifestyle hub in Tampines.
Fellow GRC MP Desmond Choo said Mr Heng's residents will be taken care of by the other four MPs.
"Tampines GRC advisers have always worked as a team. While Mr Heng recovers, we will take care of his residents," he said, adding that a pre-school education fair this weekend that Mr Heng started will continue."That is what he would want."