welcome to HealthcareMagic
If the urine report is normal and the ultrasound
is also normal the the hot urine or burning due to it can be due to less amount of water intake so the first thing you can do is to increase the intake of water.And if the burning still persists then you need to consult a Urologist
for examination and if required he may advise you and do a cystoscopy
to see if there is any problem in your urinary tract
like a stricture or some obstruction or internal injury.Please consult a Uroogist.