it's normal that cpu temperature is 99 to 100 in dell inspiron 3593

It Depends . 

If you are running a stress test on Processor for some time the temps can reach that level. 

At 100 degrees in order to reduce temps BIOS will send instructions to CPU to lower it's speeds. 

This is not a gaming machine so cooling won't be that effective on high loads. 

You can Disable Turbo boot to get better temps BIOS (F2) > Performance > Turn of Intel Turbo boost.  

You can also install dell power manager and change Fan settings to COOL 

Also what about the temperatures during regular use? Should be below 60 while not being stressed. 

im worry becausec the temperature most the times is 99 -100 not only for 2 second but it's ok for me if that normal for inspiron 3593

if i don't do any think the temperature around 60

i turned off Turbo boost then stress the laptop the temperature most the times around 80 to 85 it's ok or there is problem

can anyone help me please

Once again you are checking the temperatures while doing a stress test on Machine so it's normal to have high temps during a stress test. 

During Normal usages 98-99 temperature is not normal 

Just open Half a dozen Chrome tabs and a few documents (A normal use scenario) Whats the temperature now  

if something like open Chrome tabs and a few documents temperature will be around 60

Than whats the issue ?? 

If with normal usages temperatures are normal , what the issue is ?

This is not a gaming notebook or XPS where you will run stress tests to evaluate temperature control.

During a stress machine will reach high temperatures