Yes, it is.
The Minister of Employment and Labour issued a directive on Health and Safety in the Workplace on 28 April 2020 which was published under Government Gazette number 43257 on 29 April 2020
Clause 21 specifically deals with symptom screening in the workplace and states the following:
21. Every employer must take measures to –
21.1 screen any worker, at the time that they report for work, to ascertain whether they have any of the observable symptoms associated with COVID-19, namely fever, cough, sore throat, redness of eyes or shortness of breath (or difficulty in breathing);
21.2 require every worker to report whether they suffer from any of the following additional symptoms: body aches, loss of smell or loss of taste, nausea, vomiting, diarrhoea, fatigue, weakness or tiredness; and
21.3 require workers to immediately inform the employer if they experience any of the symptoms in sub-clauses 21.1 and 21.2 while at work.
Clause 21 obligates employers to screen their employees at the time that they report for work, i.e. daily and/or each time an employee enters the work premises, to ascertain whether they have any observable symptoms associated with COVID-19.
In order for an employer to screen for fever, one of the observable symptoms of COVID-19, they are required to conduct a temperature test. Accordingly, employers are legally required to conduct temperature tests daily in the workplace.