Yes, every teahouse provides hot shower on this trek. At an additional cost, you can get hot running water in bathrooms at Lukla, Namche, Tengboche, and Dingboche. At these places, teahouses charge $3-4 per hot shower. After Dingboche, you can get only a bucket hot shower with an extra cost of $5-6. The cost of a hot shower depends upon the facility at lodges and elevation.