Hello from JustAnswer.
It certainly could be related to heat or sweat, but it could be from the virus or a reaction to the medicine.
Could you attach a picture of the rash?
I had requested a picture of the rash and have not heard back.
If there is uncertainty about whether the rash is related to sweat or heat, then it would be reasonable to try regular cleaning and application of cool compresses to the locations of the rash to see if it helps improve the rash.
If it is a rash from the virus, it will resolve as the virus resolves and no specific intervention is necessary.
If it is a reaction to a medicine that is being taken, that is potentially a greater concern. The rash, itself, is not so much a concern, but someone that is having a reaction in the skin is also at risk of having a systemic reaction, and systemic reactions would be more of a concern.
At this point, it is reasonable to try the cleaning and cool compresses to see if it helps, but if you can attach a picture of the rash, I can comment upon whether any other interventions may be appropriate.