here is pet bowl heater
http://www.walmart.com/ip/Farm-Innovators-Heated-Pet-Bowl-1-Gallon-Blue/14660250
or if u can put the water under something than u make a cookie tin heater n then put your pan on it
cookie tin heater by hinkjc
https://www.backyardchickens.com/forum/viewtopic.php?id=107951
lowes
EasyHeat Plug In Thermostat they r located over by water pipes section
http://www.lowes.com/pd_21563-72436...syheat&pl=1¤tURL=/pl__0__s?Ntt=easyheat
http://www.walmart.com/ip/Farm-Innovators-Heated-Pet-Bowl-1-Gallon-Blue/14660250
or if u can put the water under something than u make a cookie tin heater n then put your pan on it
cookie tin heater by hinkjc
https://www.backyardchickens.com/forum/viewtopic.php?id=107951
lowes
EasyHeat Plug In Thermostat they r located over by water pipes section
http://www.lowes.com/pd_21563-72436...syheat&pl=1¤tURL=/pl__0__s?Ntt=easyheat