Someone should make a radiation player type and a water item (i dunno what in)
so then if someone enters a desert or something, you could put a brick that has something like these events
1. [X] Onplayer touch> self> ifClientindatabase
2. [X] Onvariablefalse> self> addClienttodatabase
3. [X] Onvariabletrue>self> removeClientfromdatabase
4. [X] Onvariablefalse>player>changeDatablock>Radiation player
5. [X] Onvariabletrue>player>changeDatablock>no-jetplayer
You would need BLID database events though :/