That seems pretty high to me. 80-85 is more like it.

Yep, I set my heat mats to get a soil temp of 83 last year and they varied a couple degrees either way. I have seen some say they go into the upper 80's to 90 but I don't think anyone would advocate much over 90. Lower 80's seems to work fine and my first year I germinated in the lower 70's and it worked fine...just took a day or two longer. But I have heat mats now so I try for the preferred lower 80's like Edymnion.
Bruce

85-90 induces the fastest germination.

My house is kept at anywhere from 72F-74F. My seed mat raises temps about 10F above ambient. 82F-84F seems like perfect temps to get seeds to wake up. 98F sounds pretty hot to me and even full on pepper plants don't like temps that high all the time.

I haven't seen anyone mention mold in the germination bed. I got mold in one of my germinating bags (garbage seeds so no loss). I bet the higher temps promote mold growth - the higher the hungrier.

Thanks fellas for your input! I've started 6 varieties in my prop chamber @ 85F. I was pretty sure 98F was too hot! I'll keep ya posted!