I did a hot water bath today. Temp was 42C or around 110F. I was able to say in for 40 minutes before my hands got pins and needles and soon after could hardly close them, my fingers were straight could hardly bend. I pulled the plug and got on my knees, head to the tub. I turned on a cool shower. It took me about 4 minutes to stabilize my breathing and move my hands again. What happened did I hyperventilate? Am I doing this wrong? How can I improve?

May I do hotter water for a shorter period? There is a point where too hot of water can harm me? Aside from physical burning of course.